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JOURNAL

OF THE

ROYAL MICROSCOPICAL SOCIETY:

CONTAINING ITS TRANSACTIONS AND PROCEEDINGS,

AND A SUMMARY OF CURRENT RESEARCHES RELATING TO ZOooLwtLoGy AND BOTAN YT (principally Invertebrata and Cryptegamia), MICROSCOPYW, Sz.

Edited by

FRANK CRISP, LL.B. B.A, One of the Secretaries of the Society and a Vice-President and Treasurer of the Linnean Society of London ;

WITH THE ASSISTANCE OF THE PUBLICATION COMMITTEE AND

A. W. BENNETT, M.A., B.Sc., ¥F. JEFFREY BELL, M.A., Lecturer on Botany at St. Thomas's Hospital, Professor of Comparative Anatoury in Ki ing’s College

S. O. RIDLEY, M.A., of the British Museum, JOHN MAYALL, Jon.,

anD FRANK H. BEDDARD, M.A., FELLOWS OF THE SOCIETY.

Ser ll V OE IV PARA:

PUBLISHED FOR THE SOCIETY BY -

WILLIAMS & NORGATE, LONDON AND EDINBURGH. 1884.

GD =P)

0

JAN 20 1

Royal Microscopical Society,

(Founded in 1839. Incorporated by Royal Charter in 1866.)

The Society was established for the communication and discussion of observations and discoveries (1) tending to improvements in the con- struction and mode of application of the Microscope, or (2) relating to Biological or other subjects of Microscopical Research.

It consists of Ordinary, Honorary, and Ex-officio Fellows.

Ordinary Fellows are elected on a Certificate of Recommendation signed by three Fellows, stating the names, residence, description, &c., of the Candidate, of whom one of the proposers must have personal knowledge. The Certificate is read at a Monthly Meeting, and the Candidate balloted for at the succeeding Meeting.

The Annual Subscription is £2 2s., payable in advance on election, and subsequently on Ist January annually, with an Entrance Fee of £2 2s. Future payments of the former may be compounded for at any time for £31 10s. Fellows elected at a meeting subsequent to that in February are only called upon for a proportionate part of the first year’s subscription, and Fellows absent from the United Kingdom for a year, or perma- ney residing abroad, are exempt from one-half the subscription during absence.

Honorary Fellows (limited to 50), consisting of persons eminent in Microscopical or Biological Science, are elected on the recommendation of three Fellows and the approval of the Council.

Ex-officio Fellows (limited to 100) consist of the Presidents for the time being of such Societies at home and abroad as the Council may recommend and a Monthly Meeting approve. They are entitled to receive the Society’s Publications, and to exercise all other privileges of Fellows, except voting, but are not required to pay any Entrance Fee or Annual Subscription.

The Council, in whom the management of the affairs of the Society is vested, is elected annually, and is composed of the President, four Vice- Presidents, Treasurer, two Secretaries, and twelve other Fellows.

The Meetings are held on the second Wednesday in each month, from October to June, in the Society’s Library at King’s College, Strand, W.C. (commencing at 8 p.m.). Visitors are admitted by the introduction of Fellows.

In each Session two additional evenings are devoted to the exhibition of Instruments, Apparatus, and Objects of novelty or interest relating to the Microscope or the subjects of Microscopical Research.

The Journal, containing the Transactions and Proceedings of the Society, with a Summary of Current Researches relating to Zoology and Botany (principally Invertebrata and Cryptogamia), Microscopy, &c., is published bi-monthly, and is forwarded gratis to all Ordinary and Ex- officio Fellows residing in countries within the Postal Union.

The Library, with the Instruments, Apparatus, and Cabinet of Objects, is open for the use of Fellows daily (except Saturdays) from 10 a.m. to 5 p.m., and on Wednesdays from 7 to 10 p.m. also. It is closed during August.

Forms of proposal for Fellowship, and any further information, may be obtained by application to the Secretaries, or Assistant-Secretary, at the Library of the Society, King’s College, Strand, W.C. a 2

p atron.

HIS ROYAL HIGHNESS ALBERT EDWARD, PRINCE OF WALES, K.G., G.C.B., F.BS., &e.

RD PARED AAD IDI DIDI III IDI

Past-Presioents.

Elected. Ricuarp Owen, C.B., M.D., D.C.L., LU.D., F.R.S....... 1840-1 Jonas) binge, ID). WSs Goon 6c od0osobo0dDdGDDOONS 1842-3 ‘Wrong [Bian Wish og occ oo Gago Ao OUD Do UgDOCa00000 1844-5 James Scort BowerBank, LL.D., F.B.S...........006- 1846-7 Giamncin Joie Iliteh oo gobo acaoodoadag Dodo ddDOOoe Dd 1848-9 /Aipimnons Lina, WiGID SS Teese Shes adecdc5oa050oGdnda0 1850-1 (Ginoein GiNorONt, WE OUS6 GooguooboogGonondooeosdac 1852-38 Wituiam Bensamin Carpenter, C.B.,M.D.,LL.D.,F.R.S. 1854-5 GORGE SHADBOLD sche tio Seidusiai sw ote tones wie eis eats eels euetels 1856-7 Epwin Langester, M.D., LL.D., F.R.S................ 1858-9 Gui SMstonens) Qheistenin wa Jesbao gosqu0ccab0gac0d0n0K 1860 Ropert JAMES Farrants, F.R.C.S............ a bec eed ea 1861-2 GHARGES DROOKE; (MEAL. SH RS. cc cies e oles were aires 1863-4 Jisunnry (Cnnisriiay Wo vSBs 566 ScoGsG 0505550 000000K0 1865-6-7-8 Rev. JosupH Banonort Reapz, M.A., F.R.S........... 1869-70 Vili TAM OTOHEN HARKER iHohy.So\rietelsencisies cies ceelereneie 1871-2 @HARUNS He DROOKE, HVAC HOR Sng. «cto eee co oar etes 1873-4 Henry Currton Sorsy, LU.D., F.R.S................ 1875-6-7 Henry James Suack, F.G.8....... aye. wile SW 2ANe alate re eae ee 1878 LioneL 8. Beane, M.B., F.R.C.P., F.R.S.............. 1879-80

Pe AR TIN eUINCAN.@OVL, Ek hveSo less tierelelc «nee 1881-2-3

COUNCIL:

Euectep 13TH Fesruary, 1884.

Areswent. Rev. W. H. Datuineer, F.R.S.

Vice-Presidents, Joun AntHony, Esq., M.D., F.R.C.P.L. Pror. P. Martin Duncan, M.B., F.BS. James GuatsHer, Esq., F.R.S., F.R.A.S. *CHaRLES StEwart, Esq., M.R.C.S., F.L.S.

Creusurer, Lionen §. Bratz, Hsq., M.B., F.R.C.P., F.R.S.

Secretaries, *Frank Crisp, Esq., LL.B., B.A., V.P. & Treas. LS. Proressor F. Jerrrey Bewu, M.A., F.Z.S.

Ciwelve other Tlembers of Council.

ALFRED WILLIAM Bennett, Esq., M.A., B.Sc., F.L.S.

*“Rospert Braituwaite, Esq., M.D., M.R.C.S., F.L.S. G. F. Dowprswett, Esq., M.A.

J. Wixi1am Groves, Esq.

Joun H. Ineren, Esq. Joun Martuews, Esq., M.D.

Joun Mayatt, Esq., Jun.

Apert D. Micnart, Esq., F.LS.

*Joun Miniar, Esq., L.R.C.P.Edin., F.L.S. Witiram Mitztar Orp, Esq., M.D., F.R.C.P. Urpan Pritonarp, Esq., M.D.

Witu1am Tuomas Surroix, Esq.

Hrbrarian and Assistant Secretarp. Mr. James West.

* Members of the Publication Committee.

i wy ¥ 4,

{ hy,

ee

CONTENTS.

TRANSACTIONS OF THE SocIETY—

I.—The Constituents of Sewage in the Mud of the Thames. By Lionel 8. Beale, F.R.S., Treas. R.M.S. (PlatesI.-IV.) Partl 1

II.—On the Mode of Vision with Objectives of Wide Aperture. By Prof. E. Abbe, Hon. F.R.M.S. (Figs.1-7) .. .. 4, 20

III,—Observations on the Life-History of Stephanoceros Hich- horn. By T. B. Rosseter, F.R.M.S. (Plate V. Figs. 1-3.) Part 2 169

IV.—The President’s Address. By Prof. P. Martin Rae Tg tasty \WWoltGLESI es 54 0 a6) on co ep 173

V.—On the Mineral Cyprusite. By Julien Deby,C.E.,F.R.MS. _,, 186

VI—List of Desmidies found in gatherings made in the neighbourhood of Lake Windermere during 1883. By J. P. Bisset. (Plate VY. Higs.4-7).. .. .. «o «. 45 192

VII.—On the Formation and Growth of Cells in the Genus Polysiphonia. By George Massee, F.R.M.S. (Plate VI.) ,, 198

VIII.—On the Estimation of Aperture in the Microscope. By the late Charles Hockin, jun. (Plate VIL) .. .. .. Part3 337

IX.—Note on the Proper Definition of the Amplifying Power of a Lens or ert ahs Prof, E. aay Hon. F.R.M.S.

PAGE

(ities 43) 00 90 5a ae G0, (00 00'. 00 Go. 00. 348 X.—On Certain Filaments observed in Surirella bifrons. By John Badcock, F.R.M.S. (Figs.49 and 50) .. .. i 352

XI.—Researches on the Structure of the Cell-walls of Diatoms. By Dr. J. H. L. Flogel. (Plates VIII. and IX.) .. .. Part 4 505

XII.—On a New Microtome. By C. Hilton eee te td igs 83 and 84) Sry cath Geis 00 3 523

XIII.—On some Appearances in the Blood of veep hes with Reference to the Occurrence of Bacteria therein. By G. F. Dowdeswell, M.A., F.R.M.S., &. «2 «2 26 «2 525

XIV.—On Protospongia pedicellata, a new compound Infusorian. By Frederick Oxley, F.R.M.S. (Figs. 85 and 86).. .. 5, 530 XV.—On a New Form of ee Prism. mh C. D. Ahrens. (Higss SiiandiSS) ies. aes <-- sce XVI.—Researches on the Structure of the Cell-walls ¢ of Diatoms (continued). By Dr. J. H. L. ore ee IX., X. and XI. and fig. 119) .. .. .. .. o Part 5 665

XVIL—On Drawing Prisms. By J. reagents M.D. Cantab., F.R.C.P., F.R.M.S. (Figs. 120-2) .. .. .. tA 5s 697

Vill CONTENTS.

PAGE XVIIL.—Description and Life-history of a new Fungus, Milowia nivea. By G. Massee, F.R.M.S. (Plate XID.) .. .. «. . Part 6 844

XIX.—Notes on the Structural Characters of the Spines of Echinoidea. (Cidaride.) ae Prof. F. Jeffrey Bell, M.A., rSTeXce 70). = i @/ ed [2h vey Ul ES) Yer ODIO 5s 846

XX.— Researches on the Structure of the Cell-walls of ee

Eupodiscus. By Dr. J. H. L. Flogel. (Fig: 144) .. .. ,, 851 - XXI.—On some Photographs of Broken Diatom Valves, taken by Lamplight. By Jacob D. Cox, LL.D., F.R.MS. .. .. 853

SuMMARY OF CURRENT RESEARCHES RELATING TO ZOOLOGY AND BoTANY (PRINCI- PALLY INVERTEBRATA AND CRyYpPTOGAMIA), Microscopy, &c., INCLUDING ORIGINAL COMMUNICATIONS FROM FELLOWS AND OTHERs.*

27, 201, 354, 535, 704, 859

ZOOLOGY.

A.-—GENERAL, including Embryology and Histology of the WORE, Influence of Gravity on Cell-division .. .. so pa Leta I OT Influence of Physico-Chemical Agencies upon the Devon

ment of the Tadpoles of Rana esculenta . : ee 29 Colours of Feathers .. . (tia icici ll Gone MpoMatzcsth ios 29 Rudimentary Sight apart rer om Eyes Gp.) te onl don Sony mics 31 Commensalism between a Fishanda Medusa .. . % 35

Development of the Optic and paca y Organs of iFosmen

Embryos 00 co oo oo deta PADI Eggs of Birds .. rs 203 Chemical Composition ys the Hog apa its Brvcopes im the

Common Frog .. + Sy pegeleyp Mesee te aeis mss 203 Zoonerythrine and other As) PyTeao a Sees ati: Sea ence 204

Commensalism between a Fish anda Meduse .. .. 5 204 Contributions to the History of the Constitution of the

OWL. 00 00 08 30 00 0a oo oo oo Lents} Bast Origin of Detar 4c Siamentatie 00 00g 355

Gastrea Theory .. .. 00 357 Changes of the Generative Daadhnais before Geese. Ae ote eh 357 Development of Spermatozoa eae weyers ee immer, 359 Human Embryo .. . aM Abate Cee ase a 359 Placentoid Organ in ihe Binbr yo of Bir oe A ica: Cicaew 360 Development of the Spinal Nerves oe Tritons so Rey aes 360 FRUIT Off JHAGRUOWEMS co 0p 00 0000 assis 360 Development of Lacer in ag gilis ae 861 Development of Teleostei ” : Shas Got gh 362 Influence of High Pressures on assay Baepinsine Re eaae gs 362 On some Appearances in the Blood of Vertebrated Animals

with reference to the Occurrence of Bacteria therein .. Part 4 525

* Tn order to make the classification complete, (1) the papers printed in the <p: ansactions,’ (2) the abstracts of the ‘ Bibliography,’ and (3) the notes printed in the ‘ Proceedings ° are included here.

CONTENTS.

Polar Globules and other Elements eliminated from the . Part 4

Ovum.. .. , BO Embryonic Germinal Havers cine he Tissues Bp Origin of the Mesoblast of Cartilaginous Fishes ..

Intra-cellular Digestion in the Germinal Membrane of

Vertebrates .. Oc Larval Theory of the Origin of Coli Tse, ; Development of Protovertebre 90 60 0 Experiments in Arrested Development .. .. . Morphology of the Directive Corpuscles .. .. Morphology of the Pineal Gland.. Bp Segmentation of the Vertebrate Body.. .. 00 Embryology of Alytes obstetricans .. 1. «. oo» Development of the Nervous System of irae 00

Incubation of Eggs in Confined Air—Influence of Ventilation

on Embryonic Development Embryology of the Sheep .. «sae Development of the Generative Organs Spermatogenesis seal) ccamteparacerNae sie JHCHOTS Off SHRUGWU) 00 50 oo 00 00 Rudimentary Placenta in Birds... .. 1. « Permanence of Larval Conditions in Amphibia .. Embryo Fishes 00 00. 08 06 Development of Viviparous inane 00-00 00 Formation of and Reaction of Nuclei.. .. Indirect Nuclear Division .. .. Nucleus of the Auditory Epithelium of Ratneadsene Hpidermis of the Chick.. .. .. «» Scales, Feathers, and Hairs... 60 OC Locomotion of Animals over smooth Werte Surfaces Zoology of the Voyage of the‘ Alert? .. .. 1. a Physiology of Protoplasmic Movemsnt. oo) Wpouh coe

. Part 6

Power of Reducing Silver possessed by Animal nen

Fetus of Gorilla .. ..

Influence of Magnetism on the Dosebarnons of the raha YO

Blastopore of the Newt.. Natural and Artificial Fer Heaton af eaeng One Development of Pelagic Fish Eggs

Cell-division, the Relation of its direction to Gravity aur

other Forces .. . 2 oO Aspects of the Body in Web ae and Aes parce ae Observations on Vegetable and Animal Cells

B. —INVERTEBRATA. Nerve-centres of Invertebrata a0. 60 Tracks of Terrestrial and Fresh-water Animals ..

Growth of Carapace of Crustacea and of Shell e Mollusca

Symbiosis of Algew and Animals .. .. Annelid Commensal with a Coral.. «. Intra-cellular Digestion of Invertebrates

OO

On

eo

”? .» Part 5

Part 1

tb)

92

. Pant 2 . Part 3 Lifect of High Pressure on the Vitality of Micro-organisms Part 4

CONTENTS.

PAGE Micro-organisms of the Deep Sea She GO Spee Loe ore latrines te 317) Origin and Formation of Glairine or Barégineg .. .- «.. 4 547

Organisms in Hailstones ,. 46 26 os «6 oF 4 548 Origin of Fresh-water Faune .. «1 ae +e ae «» Part5 719 Pelagic Fauna of Fresh-water Lakes .. .. » 720 Lowest and Smallest Forms of ae as iN a the

modern Microscope .. «+. He Wer iitecact te felegh lune sis 721

Intelligence in the Lowest AaSipat Bote CGOM cut 06", tooLce Gi} 725 Function of Chlorophyll in Animals .. .. .» «» «« Part 6 866 Action of High Pressures on Putrefaction, and on the

Vitality of Micro-organisms .. .» «se ce «2 «8 49 867

Mollusca. Growth of Carapace of Crustacea and a Shell of Mollusca Part1 34 Skin of Cephalopoda .. 60 00 0 60D 36 Development of Gills of antarete Bat GuoeWoo. < Oh ade an 37 Further Researches on Nudsbranchs .. .» o 8 « 4 38 Functions of the Renal Sac of Heteropoda.. .. .- ++ 4 38 Interstitial Connective Substance of Mollusca .. . « 4 39 Visual Organs in Solen sisi, Gialahee pr'eion En clohaeapale kos rere 39

General Account of the Mollusca So dd on So op Leahey) PUDED Intertropical Deep-Sea Mollusca,. .» « « «© « 9 206 New Cephalopoda... .. ss se «s+ oF «+ oe Operculum of Gasteropoda .. .. 2 « « +8 49 207 Anatomy of the Stylommatophora .. 4. «+ of oF 4 208 Segmental Organs and Podocyst of Embryonic Limacine .. Spicula Amoris of British Helices 1. +. «1 0 «8 455 210 Anatomy of Pelta and Tylodina.. .. ate Absolute Force of the Adductor Muscles e erncipaners Water-pores of the Lamellibranch-foot .. . . « 4 212 Visual Organs in Solen no 0G CO 00 00 00) 00 213 Gustatory Bulbs of Molluscs re ee atiiomcon Morphology of the Renal Organs and Cem a Coraeneds . 365 Procalistes: a young Cephalopod with Pedunculate Eyes.. Gill in some Forms of Prosobranchiate Mollusca.,. .. .«. 45 367

Kidney of Aplysia op OD ROOT OCC aor awh Ge 15 367 Visual Organs of Lamellibranchs SON Ge foc roo .ooe os 368 Suckers of Sepiola.. .. > oo « « bart 4 048 Histology of the Digestive Ghai of H Ap seg easy 549

Aplysie of the Gulf of Naples .. .. «2 «2 oF oF 9 550 Morphology of the Acephalous Mollusca .. .. «. . Bs New Type of Mollusc .. .. 00 60 00 050 LEHR) 727/ Taking-in of Water in Relation to the Vesories System of Molluscs .. .. e

Eyes and other Shranaasens m the Shells # Chitonidee Renal Organs of Embryos of Helic .. .. .. «2 «8 45 729 Nervous System of Parmophorus australis .. 3 Organization of Haliotis .. ee eee os oe 730 Absorption of the Shell in Aur ceueeen do oo oo co oa gf 730 Development of the Digestive Tube of Limacina.. : © Operculum and Foot-glands of Gastropoda... .. .. « Part 6 869

CONTENTS.

Latent Period in the Muscles of Helix a5 100 Affinities of Onchidia .. 416 Dimorphism of the Spermatozoa in Paladin

Mode of Action of Shell- and Rock-boring Molluscs .

Action of Sea Water on Molluscs

Molluscoida.

Egg and Egg-membranes of Tunicata ..

Simple Ascidians of the Bay of Naples

Urnatella gracilis, a Fresh-water Polyzoan Structure and Development of pgs Development of Salpa .. c 60

Budding of Anchinia .. .. 00 30 Morphology of Flustra ep neIpn- ‘eupaniie 00 Anatomy of Rhopalea ..

Simple and Compound Desirtry §

Digestion in Salpa See CW) clo Oe Fresh-water Bryozoa

Supposed New Species of Cr intelia Segmentation of Ascidians

Relation of the Nervous System of the Adult Usain %

that of the Tailed Larve .. Segmentation of Simple Ascidians Development of Social Ascidians .. Tunicata of the ‘ Triton’ Organization of Anchinia .. .. . Closure of the Cyclostomatous Bryozoa

Arthropoda.

Aspects of the Body in Vertebrates and Arthropods ..

a. Insecta, Respiratory Centre of Insects

Chordotonal Sense-organs and the Hearing of econ Number of Segments in the Head of Winged Insects...

Protective Device employed by a See igs ea

Formation of Honeycomb .. .. BD Mouth-organs of Rhynchota

Development of Genital Organs of reat Genital Ducts of Insects .. .. -. « Thoracic Musculature of Insects..

Early Developmental Stages of Viviparous ‘Aphides oC

Chlorophyll in Aphides

Genealogy of Insects

Development of Antenne in ipscats

Experiments with the Antenne of Insects .. Epidermal Glands of Caterpillars and Malachius Classification of Orthoptera and Neuroptera Sucking Organs of Flies . 30 48 Visceral Nervous System of Per pelarata antantclls

. Part 6

Pat 6

.. Part 6

. Part 1

oo ”

On ”

iG Pare 2

xl

PAGE 870 870 871 872 873

213 214 214 215 368 369 371 552 731 732 732 733 873

874 875

_ 875

878 878 879

866

217 218 218 219 220 220 223

xii

CONTENTS. a

PAGE Pulsating Organs in the ce of Hemiptera 3, :. «. Part 224 Corabus bifasciatus® “a. 25 ae feet en Ses) oe ae PAILS OIA Mouth-parts of Diptera «1 ss oe ou we ewe 372 Mouth-organs of Lepidoptera RUE nl Pehueter ose he ang 372 Malpighian Vessels of Lepidoptera .. 1. +s 1s 08 15 373 Abdominal Muscles of the Bee .. .. «» «6 «+ « 1459 373 TAO OP IMSCOD ea co od 9 OG) ba Foe Bo 8 tO, 374 Aphides of the Hlm — .. Be a rpte aae lee 374 Attraction of Insects by Phallus faa Capris: BG) 100) Oe = oh 420 ULGTOUGULCLLCT Meare ate) ele .. Part 4 552 Development of Gcanthus niveus and is paras Teleas sO 553 Origin of Bees’ Cells .. «. n0 06 oO. 00 80° 504 Closed Poison-glands of Cater lens Som uot one! dd. toa op 555 Gills of Insect Larve .. .. iva Gbe OG 5 555 Dangers from the Eacrement of Whee... 30 00 50 50g 506

New Type of Elastic Tissue, observed in the Larva of Eristalis .» « Part 5 733 Submaaxillary of the i of Mandibulate Tec reas te as 733 Structure and Function of Legs of Insects.. .. 00. oD 734 Organs of Attachment on the Tarsal Joints of Trans Spee es 736 Locomotion of Insects on Smooth Surfaces .. .. .» «8 45) 716 & 737 Organs of Flight in the Hymenoptera .. .. 500 0h 738 Poison of Hymenoptera and its Secreting Onnne. On Par Oe wey 739 Development of Cerocoma Schreberi and Stenoria apicalis.. ,, 739 Dipterous Larve .. .. of 90 bo. no. 739 Larve of North American Lepidoptera Fol ac oa DO = ep 740 Drinking Habit of a Moth .. «1 «. oh ars 741 Movements of the Heart of Insects dur eg Wctumonnnanal .. Part 6 879 TRONG® Of ISG 00 c0 00 O02 00 00 of so 880 JGGIR5 Of JPOP MOPS 00° 00 600s op 880 Sting of Mellifera 006 ae » 880

Anatomy and Functions of the Tonge of the. Hone Bee (Worker). aia Meise Aig? Ge Soap icles 55 881 “* Tgnivorous Ant ee 20 no 00 OO 882 Aquatic Lepidopterous Larve 5 882 Maxillary Palp of Lepidoptera .. ae cues 883 Development of Viviparous Aphides 0 883 Systematic Position of Pulicide .. Fa 884 Structure of Proboscis of Blow-fly » 003

8. Myriopoda. Head of Scolopendra co 0 on on LE) YEE Nerve-terminations on Antenne of Gilcanaina . «» Part 4 556 Ovum of Geophili 00°06 56 oc 5 057 y. Arachnida.

Testis of Limulus... .. .. Ad. 80 . Parti 49 Polymorphism of Sarcoptide «53 49 Vitelline Nucleus of Araneina : .. Part 2 224

Restoration of Limbs in Tarantula ..

x 225

CONTENTS.

Morphology of Plumicolous Sarcoptide ..

Skeletotrophic Tissues and Coxal Glands of Limulus,

Scorpio, and Mygale.. .. .. « Type Series of British Oribatide Poison-apparatus and Poison of Scorpions .. Structure and Function of the Liver a Spiders .. Anatomy of Acarina oth doo 60 Michael’s British Or eB. 00 aC Development of Spiders... .. .. «» « Anatomy of Spiders .. 1. 25 ss Anatomy of Epeira Auditory and Olfactory Onaere of. Beuers: Anatomy of Pentastomum Protelis .. .. Pycnogonids of the Faeroe Channel Development of Limulus

6. Crustacea.

oe

Xili

PAGE aekante2225 no Letien @) asa oe Teas 500 . Part 4 558 © Bhar 558 Sayer sy 559

Part 5 741 .. Part 6 884 oi Natio 885 sai uns 885 Ra, iss 886 Belin. $5 887 56 888 ae oad 888

Growth of Carapace of Crustacea and of Shell of Mollusca Part1 34

Spermatogenesis of Podophthalmate Crustacea ..

AGRIC ISOC «00 00 00,0 New Host for Cirolana concharum ie

Copepoda Entoparasitic in Compound Ascidians. .

Anatomy and Physiology of Sacculina .. Sexual Characters of Limulus .. ..

Ewidence of a Protozoea Stage in Crab Development...

Gastric Mill of Decapods .. ..

Spermatogenesis in Hedriophthalmate Gristacea

LL GWEP Of IUGCH NON 3 00 00 nS ‘Challenger’ Copepoda.. .. «+ « o« Longipedina Pagurti .. .. . « «o OndiGRe co on 00

Deep-Sea Crustacea .. 1. «6 «2 0 Sexual Colour- Variation in Cructeone. co. co Observations on Tanais Girstedi.. .. «. New and Rare French Crustacea., .. Stomach of Podophthalmate Crustacea Significance of the Larval Skin in Decapods New or Rare Crustacea 20 o0 Rate of Development of Conair ines Bis 9 Chuettiqnaar ° lisa@etlis 20 00 00 00 60 The Cryptoniscide .. . sausesiaaes yee Antennary Gland of Cy theriate bo. Gory 6 ‘Challenger’ Cirripedia .. ..

Vermes.

Classification of the Phyllodoceide .. .. Anatomy of Polynoina., .. .. « Spadella Marioni.. .. 1 oo New Forms of Thalassema.. .. Spermatogenesis in the Nemertinea .. Development of Trematoda-., .. ..

; Fe 50 Piney 50 2 51

: 3 51 0 51 Part 2 226 5 226 Aig 227 228

Part 3 375

AO aS 376 Fr 377

” 377 ees 377 . Part 4 560 = 561 yaeaeeas 562 . Part 5 742 aes 744 etnies 744 .- Part 6 888 Fey oy 889 jap ose 889 hae 890 se 890 » Partl 53 ates 54 9 4

”? 333)

. 55

XIV

CONTENTS.

PAGE

Simondsia paradowa 1. +s «1 +e oe oe ee os Partl 58

Monograph of the Melicertide «1 ss se ee ee eng 58 Observations on the Cy of Stephanoceros

Eichhornii. (Plate V. Figs. 1-3) .. .. .. « « Part 2 169

Annelid Commensal witha Coral.. .. .. Ran Aes lass 204 Structure and Division of Ctenodrilus pomesties au | 60 5p 229 Manayunkia speciosa .. .. « Cot: Money do wooden 6) 231 Parasitic Nematode of the Common Onin eine eat 232 New Myzostomata «ss ee ne wee ne weg 232 Bucephalus and Gasterostomum .. ++ ++ se ee eg 232 Development of Dendrocelum lacteum .. SOMEM ON Waco! iss 234 Rotatoria of Giessen «1 66 ee es wean we gg 235

Rotifer within an Acanthocystis .. «+ se 66 se +e 238 Development of Worm Larve .. «1 « «+ «+ «+ Part 3 378 Excretory Apparatus of Hirudinea .. .» ss oe es 379 Function of Pigment of Hirudinea «1 46 vu we we gg 379

Otocysts of Arenicola grubu om 880 Manayunkia speciosa .. 6s oe eee egg 380 Life-history of Thalassema.. .. os 7 381

Spermatogenesis and Fecundation in ligase pagetacetaPs ~) 382 Structure of Derostoma Benedent.. «1 «1 «6 + 08 49 383

Opisthotrema, a New Trematode .. 2. +1 +6 se oe ogg 384 Polycladidea.. . oO) oo: OO! «rp 385 Early Stages in the Developmiat 9 Balanoglsss an 388 New Rotatoria .. . : oe MKOCN UabGyy on) akeeD 888 Nervous System of eames ee de -- . Part4 564 Cerebrum of Eunice harassii, and sta Relations to the

Hypodermis. si 9 ae se ee) wel ev foe Pee incl | sy 964 Varieties of Byaneiasdeta CURIS 55 oF 95 565 Ovum and its Fertilization (in Ascaris) “ 565

Spermatogenesis in Ascaris megalocephala .. .1 «6 «+. 45 567 Spermatogenesis in Ascaris megalocephala .. .« «+ +. 4 569 Nematoids of Sheeps’ Lungs.. .. +» «6 «6 ce os 455 569 Free-living Nematodes .. 1. «+ «+ 0 4 48 06 45 570 Trichina and Trichinosis .. 1. .. 0 oF «8 oF 45 570 Cystic Stages of Teniade .. .. aah “ete ue ee es O71 Anatomy and Development of Prematoda o0 oe 5 571 Worm Fauna of Madeira Leen ded Pate. GEE Sve coe 573 Ngan Sa@egs Of IROSHGPso 00 100 00 00h 973 New Type of Hirudinea .. 41 se te we -- Part 5 744 Structure of the Branchie in Shommioscr 3G) “ob od ogy 745 Structure and Development of Fresh-water Dendrocela .. ,, 746 Glassification of the Rotifera). <2 ss es) es oly Iie IPqag i IHU 000 sisit,si HG EY Head-kidney of Polygordius 50. 00 1 6D) 90 OD) oo 892 Nervous System of the Archiannelid@ .. 1. «6 1 o 4) 893 ALE OMO) OF GG JORGUTAD 55 60 00 of op oo co 893 External Morphology of the Leech .. « . ban 896 Action of a Secretion obtained from the Medicinal ieee on

the Coagulation of the Blood .. «1 12 se oF oF 896 Organization of Echinorhynchi .. .. ab gy 897

CONTENTS. KV

PAGE Biatozoic Worms > yas) ae) cep 1 -o, ee) emesis EOXtG SUS Nervous System of Trematodes .. .. 30 5 898 Rhabdocela from the Depths of the Lake ap Geneva Be poe 898 Physiology of a Green Planarian.. .. 35 899 Worthington Smith on Diseases of Field ae) benean Orvis a 935 Echinodermata. Histology of Echinodermata...» «+ « « « « Partl 60 Nervous System of Holothurians .. ss «1 «+ «6 oF 4 62 Vascular System of Echinoderms.. «6 «6 «+ «6 «+ 4% 63 Echinoderm Morphology «+s se ve we we we Part 3 389 Development of Comatula .. «6 «5 66 «6 oe ee og 389 Pharynz of an unknown Holothurian .. .. «1 5 +8 59 390 Nervous System of the Crinoidea ae [0 901 Development of the Germinal Layers of ennecernae .. «. Part4 573 New Genus of Echinoids .. «6 21 ++ 66 0 eg 574 Revision of the Genus Oreaster .. .. +» ++ ee te oy 574 Organization of Adult Comatulide ., «+ +» « «+ 5 575 Constitution of Echinoderms JOE Ney haa, bo AU ONO Pourtalesia .. act Sao meicee. CaouN ecb ieee aT 751 Anatomy of ihe Coieatte oc es we OL

Notes on the Structural Sienaatare ee the “Sings of Echinoidea. (Cidaride.) es XIII. . ee ariOMsto

Structure of Echinoderms .. .. + 50-00» yooN tp 900 Nervous System of Antedon rosaceus .. .. «+ «+ 4 4 901 Nervous System of Crinoidea ... Het. gsm teh 902 Asteroidea of the Norwegian North Se, 1 Eapetition els vai8 a 903 Mimaster,anew Asterid .. .. « aoe stosa boom alan 903

Amphicyclus, a new Holothurian .. .. «1 «+ 08 8 ys 903 Cuvierian Organs of the Cotton-spinner «1 + we we oy 904

Ccelenterata.

Commensalism between a Fish and a Medusa .. .. . Partl 35 Nervous System of Porpita .. .. +6 «+ «5 24 08 59 64 Bermudan Medusa .. « . CU cans Sorel, ten Commensalism between a Fish aid a Medusa Pee ae bart 2) 204

Annelid Commensal with a Coral tion Ba 5 204 New Alcyonarians, Gorgonids, and Pennabialds of the Norwegian Seas Jouiscee AeaGndetic o Nop | A0do Wop alco, Okrp 239

Origin of Coral Reefs 2. .. «5 + 06 «2 ef 22 9 240 Porpitide and Velellide 1. ss 0» «6 06 6 «8 59 241 Mesenterial Filaments of Alcyonaria .. .. .» «. «. Part3 390 Anatomy of Peachia hastata .. ss oe oe we wos 391 Ephyre of Cotylorhiza and Rhizostoma .. «. «. «+ 9 391

Anatomy of Campanularide eu aa Wee ae oe bart of: Structure of the Velellide .. 1. .« «2 «8 «8 oF 9 576 Actinie of the Bay of Naples .. «1 «2 «1 2» «8 O77 Notestonn cds ae ee te eee oem kart ooo

Revision of the Maireporaria ate eet set eee <5 759

xvl

CONTENTS.

Porifera. Alleged new Type of Sponge 6a bu 00 Biology and Anatomy of Clione .. .. New Siliceous Sponges from the Congo Honan Physiology of Gemmuules of Spongilide .. .. European Fresh-water Sponges .. .. New Genus of Sponges .. Calcisponges of the * Challenger ” Biyactiean Australian Monactinellida .. +s» «ss s+ Japanese Lithistide .. . a> Go 00 Fossil Sponges in the British icon 00 | 66 Vosmaer’s Manual of the Sponges 00 New Gastreades from the Deep Sea .. .. Siliceous Spicules of Sponges Fresh-water Sponges and the Pollution: of Riveronater Vosmaer’s Sponges noo Fresh-water Sponges .. «+

Protozoa.

Parasitic Infusoria oo . «2 New Infusoria .. .

Relationship of the Hageliata to une ae Winsor Transformation of Flagellata into ee vie Stein’s ‘ Infusionsthiere? = 6. se aw Cilto-Flagellata .. New Choano-Flagellata

Anatomy of Sticholonche zanclea ob on

Studies on the Foraminifera ook wn 00 Development of Stylorhynchus ..

Trichocysts of Paramecium 00

Biitschli’s ‘ Protozoa’ New Infusoria ; Reproduction in Leoielasins feast Orders of the Radiolaria Bohemian Nebelide .. 50 Action of Tannin on Infusoria .. ae Nucleus and Nuclear Division in Protozoa New Infusoria Stentor ceruleus 20 Chlorophyll-corpuscles of some ricony on Life-history of Clathrulina elegans Aberrant Sporozoon Noctilucide .. .. ..

eo oo eo

eo eo

eo eo ec ee

ee eo

On Protospongia (soeeaieaten a new Consened Injusrin

(Figs. 85 and 86) .. .. : Morphology and Anatomy of Ciliated Oy auR Trichomonas vaginalis .. oc a0 Acanthometra hemicompressa Orbulina universa .. 90°. a0 Nuclear Division in Ba osrhaninn eichhornit .. New Infusoria ..

eo ee eo eo oe

PAGE eRaxt loo: 5 65

ac Ness 66 . Part 2 241 th 242

5 243 Part 3 392 5 394

a 395

55 396

Oat es 397 . Part 5 756 5 757 757

Part 6 904 » L004 Part l 67 »» 68

” 68

» 369

” 70

” 72

” 73

9 73 age

” 74 157

Part 2 243 “3 244.

i 245

“ 246

5 247 305

Part 3 398 5 401

35 401

Fe 401

Pa 402

% 403

7; 403 Part 4 530 ey rT

5 579

» 979

ns 579 580

CONTENTS. XVii

PAGE Parasitic Peridinian wows wy ws te a ae, Part 5 759 Observations on Flagellata .. 1. ++ «5 06 28 4s 145 759 Geometry of Radiolaria «1 ss se ue te tet 759 Polythalamian from a Saline Pond dhe Wencie c0n4) ch ease wat) 760 Nuclear Division in Actinospherium eichhornii .. 1 «+ 455 761 Parasite of the Wall of the Intestine v WNC 1EOFSA 6a 50 762 Sutherlandshire‘ Fozoon”” .. «. Poe eee, Owen 763 Nuclei of Infusoria .. Ce a) eke eartson. 90 ae New Infusor p= Ciatictere abantioentatl Kaas! — 55 905 New Fresh-water Infusoria 60 sin | Oe: (96 4600, Lage ssp 907 Life-history of Stentor ceruleus nih WROLe Aho hAb Om omane 907 New Rhizopods and Vorticelle .. .» . « «© « 4 908

‘ Challenger’ Foraminifera BS eOG: 1omDO | ROG: (ROE: Sonne 909 Copulation in Difflugia globulosa .. «1 +1 ws we 911 Development of Stylorhynchus longicollis .. «1 «» «+ 45 912 Flagellated Organisms in Blood of Animals Boi oe hee 913 Parasitic Proteromonadid@ .. .. s» «ss «+ «F oF 49 913 Bacterioidomonas sporifera ae a0 | ip 934 Influence of Gravitation on the iene of Gann

domonas and Euglena 14 11 we ws $5 938

BOTANY. A.—GENERAL, including Embryology and Histology of the Phanerogamia, Relations of Protoplasm and Cell-wall in the Vegetable Cell. Part 1 75

Intercellular Connection of Protoplasts .. «+ « «+ 4 76 Polyembryony of Trifolium pratense . nine gecan teeth ness 76 Mechanical Structure of Pollen-grains 50 0D oo gh 76 Fertilization of Philodendron .. ss +» ee tn 6 TT Fertilization of the Prickly Pear.. .. .» « cee Pa 77 Annual Development of Bast 1. «» «1 «+ Te Lenticels and the mode of their replacement in some weootly

tissues a Es oe ae Se sions, (aus asta cea Teed oss 78 Gum-cells of Cereals Sol hdoe abi ods Boll ap x 78 Nucleus in Amylaceous Wood-cells .. «1 08 « 5 79 Peculiar Stomata in Conifere@ .. .» +» ae oe wag 79 IBOORGETS co on ob a0 cd Go 00 aC % 79 Steve-tubes of Cucurbita ape Perrone Mcietadkaclela (= sinus Mitel aest oll Ja's5 81 Spines of the Aurantiacee .. .. «6 es we we wg 81 Tubers of Myrmecodia echinata .. .. 50g 81 Chlorophyll-grains, their Chemical, Mor, phological, and

Biological Nature .. . ais os we ie Pa 81 Mechanism of the Splitting of enunee O° 5 82 Aerial Vegetative Organs of Orchidee in relation to Rap

Habitat and Climate... .. « 30 *H 83 Assimilation of Carbonic Acid by pentoniaen sonich ne

not contain Chlorophyll .. .. 9000. ¢p 83 Artificial Influences on Internal Cutises of Gronth S8.oP BD <5 83 Absorption of Food by the Leaves of Drosera.» +» «+ 4 83 Mechanical Action of Light on Plants op «OO . 84 Action of the Amount of Heat and of Maximum Tae.

perature on the Opening of Flowers APY Reco aiaeeo. TaLOom ale 85

Ser. 2.—Vot. IV. b

Xvi

CONTENTS.

Behaviour of Vegetable Tissues towards Gases .. .. «. Influence of External Pressure on the Absorption of Water OY LEGO sn dco oc ; eye Contrivances for the Erect Habit of es and Vafiaices of Transpiration on the Absorption of Water.. : Sap oo “oth, /bos Mook on Solid Ppeants m ve Cig aii wi 20 30 Movement of Sap in Plants in the Trees : : Exudation from Flowers in Relation to Honey-dew .. Latex of the Euphorbiacee .. 3 Crystalloids in Trophoplasts and Chromeplats of Angio

SPErMS ne. ae 40 , Formation and Resngatiinn of Cystoliths Bae PN ae Un Functions of Organic Acids in Plants.. .. ar

Formation of Ferments in the Cells of ie Pins 3c

Poulsen’s Botanical Micro-Chemistry . es

Living and Dead Protoplasm

Aldehydic Nature of Protoplasm bo 90 00

Embryo-sac and Endosperm of iar Boe 0G: 'do

Constitution of Albumin... 56% Ibe. Fe

Fertilization of Sarracenia uma Gil o5 Ab Pe

Sexual Relations in Monecious and Diccious Plants 30

Corpuscula of Gymnosperms .. ..

Comparative Structure of the Aerial oui slibtenr raneous Stem of Dicotyledons .. .

Function of Root and Stem in “Diactaieties ee Mone cotyledons.. .. soda cexolal syaice eco autorsadecisObamess

Suberin of the Cork- ay oc

Influence of Pressure on the Groen and Str ctu é of Bap ke

Relation of Transpiration to Internal Processes of Growth

Easily Oxidizable Constituents of Plants ..

Action of Light on the Elimination of Oxygen ..

Red Pigment of Flowering Plants .. . 00 > 00 Coloured Roots and other Coloured Parts of Plants 50 Starch in the Root 66 00 any) dow as

Proteids as Reserve-Food Materials 90 Leucoplastids ZOt) Hopes) Cosei-aner oop a oae ane Cleistogamous Flowers... ». 50

Cultivation of Plants in Beosmoasatag Swinton a Or ae Matter .. Sd onl Wy aGe. ab Sow ace So

Disease of the Werment JHUNP om foo bo Fide aD

Flora of Spitzbergen .. .. .. ««

Continuity of Protoplasm ..

ts and Dead Pr flag x 90

Occurrence of Protoplasm in Intercellular Gocco

Division of the Cell-nucleus .. 1. 65 ee ie Apical Cell of Phanerogams.. .. «+ +. «1 ss 0 Nettle-fibre .. .. 30

Laticiferous Tissue of Manihot Glaziovii (Cearé Rubber) 30 Laticiferous Tissue of Hevea spruceana ba 88. 00

Part 1

PAGE

85

85

91

: Dei 2 250

250 250 251 251 251 251

252

253 254 254 254 255 257 _ 257 259 259 260 260 260

260 260 261 404 405 406 406 407 408 408 409 409

CONTENTS. Development of Root-hairs .. oo. ++ «+ Symmetry of Adventitious Roots., .. aD

Penetration of branches of the Blackberry Aili the Soil Circumnutation and Twining of Stems Vegetable Acids and their Effect in Producing Fin Wiley ee

Metastasis and Transformation of Energy in Plants.. .. Action of the different Rays of Light on the Elimination v Oxygen .. . a9, 00 00a

Movements caused a Chemin Agents

Direct Observation of the Movement of Water in Pints

Rheotropism .. .. : Bee aant, yess

Transpiration- Onan m Wendy Phage

Origin and Morphology a ae ae niet) Allied Bodies 00 aD 60, 00,7 00 00° a0

Spectrum of Chlor Benaicie

Portion of the Spectrum that Decomposes Gucion DRoasFe

Chlorophyll in Cuscuta 00 oo BG Work Performed by Chlorophy a. Spherocrystals

Spherocrystals of Basra hagas 30

Calcium Oxalate in Bark °

Homology of the Reproductive Ontia m Pane ogams nd Vascular Cryptogams ..

Influence of Light and Heat on fhe Gemenition of Seeds ..

Origin of the Placenta in the Alsinee ES

Gemme of Aulacomnion palustre .. . 0

Relation between Increase and Segmentation @ Cells .

Development of Starch-grains in the Laticiferous Cells a the Euphorbiacee@ 1. «eos ee ve wwe

Constitution of Chlorophyll .. .» as

Cellulose accompanying the Formation of Gristals

Middle Lamella of the Cell-wall .. .

Intercellular Spaces between the ieee Cells as tera

Contents of Sieve-tubes.. aoe 0° oo

Organs of Secretion in the ebracatenaae

Tracheids of Gymnosperms ..

Apparatus in Leaves for Reflecting Pa.

Swellings in the Roots of Papilionacee

Origin of Adventitious Roots in Dicotyledons

Crystals of Silex in the Vascular Bundles.. ..

Effect of Heat on the Growth of Plants .. ..

Curvature of Roots

Torsion as a Cause of the Diur ral poston of Foliar 01 rgams

Assimilative Power of Leaves 0

Quantitative Relation between Ansoration’ of Light fend Assimilation ..

Causes which Modify the oer ‘Action of TEE on gens

Respiration of Leaves in Darkness o0

Movements of the Sap in the Root-tubers of tie Dahlia

Absorption of Water by the Capitulum of ee

Measurement of Turgidity ., .. + HAY aoc

D

X1x

PAGE

Part 3 409

. Part 4

”

2

409 410 410 410 411

411 412 413 413 414

415 415 415 415 415 416 416 416

581 583 583 o8t 584

584 O84 585 585 586 586 586 587 587 588 588 588 988 589 589 589

590 590 o91 591 391 592

XX

CONTENTS.

PAGE

Continuity of Protoplusm .. .. .. « «+ «s « PartS 763 » = Re Se aes Wes Me toe). 55 764 Osmotic Power of Living Protoplasm.. .. 1.2 «1 «+ 764 Structuneof Pollen-graims) Ve ts. ae se ee see 5y 764 Seeds of Abrus precatorius .. .. oo. 6p 764

Comparative Anatomy of Cotyledons gd Fititosnernie Bike Ws 765 Underground Germination of Isopyrum thalictroides .. 4, 766

Stomata of Pandanacee 4. 4. wee Ba OME cr 766 Changes in the Gland-cells of Dionea itso during Secretion .. FTL eee eee eis = 2; 766

Septal Glands of lonocctylaicne® Bree Merrie 50. ye Oc loamy 767 Secretory System of Composite .. .. «ss «+ « «+ 4 767 Chemical Constituents of Plants s. 1. «« «2 «+ « 4) 768 SUMUCHRG Of JLGUIERES 59 oo co 09 90 of op oF 769 Transparent Dots in Leaves i POUL a oba8 oem 769 Secretory System of the Root and Sie D2 ie MRE 55 770 Anatomical Structure of the Root coe, acriody. bo 1M criaalie Oey 71 Growth of Roots .. .. oo | Oy 772 Growth in length of Dentin sand RAT URES Penta: 9 0b 772 Geotropism and Hydrotropism of Roots .. .» «.. «+ 45 7173

Water-glands and Nectaries 7 emits MAR ees | 5 7173 Folds of Cellulose in the Epidermis of ‘Petals Bo. OG. | soa 773 Anatomical Structure of Cork-woods .. .. .. « «+ 45, 73 “ Filkform Apparatus” in Viscum album .. 1. «2 «2 4 773 ZACHiOnN Of Heat upon WWegeLation «a Wanye Sele eel oe 5, 774 feelations of Heat to the Sexes of Flowers .. .. 9 775 Influence of Light on the Structure of Leaves of Allium ursinum .. ig ek See 775 Effect of Light a Shade on Ry Evaetiones cas oye tice Garo wes 7795 GRA Of MWVOIEP Gp IIS gn on SS ‘5 775 Movement of Water in the Wood.. .. .. .. 2 « 776 Measurement of Transpiration .. 1. «2 «1 «1 -9 WU Exhalation of Ozone by Flowering Plants .. .. .. «. 4 717 Acids in the Cell-sap .. Beton Sete. 5 1717 New Colouring Substance fe Chloropyt vin ED. aR 778 Crysnoicne Chilorgpailics oo 00 eo 00 06 00 oo 778 Crapialis crea) CirmsgllGsG8 oo 06 oo 00 50 09 00 35 778 Spherocrystals .. . PBL Cen St eee Ps 779 Formation and ascan tine of Cystoliths nots sah Morn Wedocn) 2) oh 779 Dewlayoingos Of LGV oo ag 6000 779 New Vegetable Pigment ig ora SANSA eee rae Rose 3 780 Fish caught by Utricularia .. .. ale nora 5 781 Observations on Vegetable and Animal Cells ve) we art 6 (914 Structure and Division of the Nucleus of op 00. , 00 915 Formation of Endosperm in Daphne .. .. Ka es 915 Method of Bursting of Sporangia and Poles ; 0 916 Pollen from Funereal Garlands found in an Pouption Tomb Le oa gir 916 Swelling Proper tes of Vegetable Galeneninene Sahota Oo 1 GS 916 Hipider min lassie -Of thew hOOt) “ch |v.) a. qh eee ee OCT Lenticels ae eee ne eee cone 917

CONTENTS. Xxi

PAGE (Raps Of DRACO SUGGES “eb 66 60 on 00 co get LEC )Ir/ Structure and Growth of Palms .. .. .. .» «+ «= 4 917 Honeneqland siof Crucrfen iyi a0) simian iss 918 Resin-deposits .. . : Ge Laoag. BO: | op 918 Distribution of Teadbgoatiattalls mt) the Plant Ee 00 918 Transpiration of Plants in the Tropics .. «1 +» «0 455 919 Chemical Phenomena of the Assimilation of Plants Bo!) MBL) rep 919 Histo-Chemistry of Plants Soa SS Gr Nos Bon? wep 919 IYO COORG DON oo po 66 00 00 80° oo on Og 920 Lime and Magnesia in Plants .. .. SADA ae mein ORs 920 Easily Oxidizable Substances in Plant Sap So weReEh PRaCoeE nee 921 Action of Nitrous Oxide on Vegetation ys re 921 Silicification of Organs 60 gp 921

Influence of Solar Rays on the Te iyperitre of Tio sete es) 921

Thermic Constants in Plants .. . . 60,00 9 921 - Chemical Changes in their Relation to Micro- onpeGis eth Mery 922 Comparative Morphology of the Leaf in Vascular a gams and Gymnosperms .... 3 922 Worthington Smith on Diseases of Field oe Gurcen Cr a8 $5 935 B.—CryYPTOGAMIA.

Cryptogamia Vascularia. ; Deda: Of HMGSUE, 50. 00 00 oo cc oo oo Jeti ll BB) Classificatzonof; Opiioglossacee) ss ee ee) ae ee) os 92 Surnonime Of JEAMMOTOSTHONUB co co 06 06 00 08 92 Fructification of Fossil Ferns... .. .. .. =. «. Part 2 261 Prothallium of Struthiopteris cea Sater ae su tae h eae 262 Stigmaria .. « bi aero . Ban 3 417 Homology of the Repr aatnetine Or “ete im Phianeroqans and

Vesculem CPOjROGoRS 55 o5 co 06 so oo oo Jenn Zt Syl Origin of Roots in Ferns 6 092 Munograph of Isoete 35 093 Systematic Position of liege ere, ‘Sigillaria 7, ard

Stigmaria.. .. pat Sr ed Ee ane ath 593 Anatomy of Vascular Cryptogens 00. 0o- ao co oo Jee Fell Fertilization of Azolla .. 5 781

Comparative Morphology of tel hee mm vacua Oe togams and Gymnosperms bc no og «oS EL GDA

Apex of the Leaf in Osmunda and Te a 56 923 Rabenhorst’s Cryptogamic Flora of Germany is Vascular

Cryptogams) ft ei Nees ee een ® Bo 9 924

Muscinee.

Structure and Development of certain Spores .. .. .. Partl 93 Mucilage-Organs of Marchantiacee .. .. .. .. « Part2 262 Cephalozia .. .. poh Lah) sobs G04) op. Joo os eta, Guly/ Variations in Sekine BU) G0. unos Mech sob) abe. aoe enbenee ye Male Inflorescence of Mosses .. 5 oo oo Letty &) ‘7ASI Lesquereux and James’s Mosses of Non th Vee HOG rope Woe es 782 Braithwaite’s British Moss Flora soy op oa an oo Leer ) Be:

TE oHes JS 7090 HOSES 56 ed. Go. be on. ne) be 924

Xxll

CONTENTS.

Characee. PAGE Characee of the Argentine Republic . Part 2 263 American Species of Tolypetta eas 263 Cell-division of Characee . Part 6 925 Fungi. Alkaloids and other Substances extracted from Fungi -. Partl 94 Development of Ascomycetes 5) 94 Conidia of Peronospora as 95 LAOS VOR INGRUUT UM = 00 00st 5 95 Chytridiacee c ” 96 Phoma Gentiane, a new 5 BB aeiie jing = 96 Chrysomyxa albida 5 96 Physoderma .. 72 97 Bacilli of Tubercle 5 98 Microbia of Marine Fish 9 98 Physiology and Morphology v Allesiif Fer nant >» 98 Alcoholic Ferments .. . Foe ae + 99 Magnin’s Bacteria 9p 99 Bicentenary of Bacteria + 144 Rabenhorst’s Cryptogamic Flora °f Ge many y Ging) Part 2 264 JEM ~~ on 50. 50 ATM y Seah Ger safest ahs 264 Graphiola =. ne 5 264 Pourridié of the Vine... * 266 Oospores of the Grape Mould cp 266 Pleospora gummipara .. 0 266 Schizomycetes = 266 Fecal Bacteria ; ey Aa] Cie. es 267 Influence of Osram ee High Pressure on Bacillus anthracis .. : Pa aA ae Bee iss 267 Bacteria in the Hage Aigerse 66 op 268 Bacillus of “ Rouget” 55 268 Living Bacilli in the Cells of Valisnen aa rs 268 Simulation of the Tubercular Bacillus by Cr Tsaline ors - 269 Cultivation of Bacteria.. Bee ocala 2 30 269 Reduction of Nitrates by Recents AG 6 269 Lamelle of the Agaricini j Part 3 418 Formation of Gum in Trees . on ee wes 419 Attraction of Insects by Phallus and Coprir mus .. Fa 420 Development of Ascomycetes 5 _ 420 Fungi Parasitic on Forest Trees .. Ac a 421 Puccinia graminis on Mahonia aquifolium .. 423 Polystigma rubrum 2. ws Bs 423 New Synchytrium .. is 423 Pathogenous Mucorini, and the Myeoss of Rabbits panic by them 30 00 » 424 Micrococci of Pisiimonil pica ha ae ier < 425 Bacteria of the Cattle Deter 426 Passage of Charbon-bacteria into the Mi ilk of Animate Infected with Charbon ; oh Meare ade 427 Comparative Poisonous Action of Metals on Beier 30 427

CONTENTS, XXlil

PAGE

Micro-organisms in Soils .. .. . - . Part 3 428 Bacteria and Microscopical Algzx on the Surface of Coins in

Currency . she. (Cash Gtssimy cater Sorat aap Qepstietr creme seman eS 428

THOS Sonn ame ae MOM Ia Manco RNcn ison. hc) Bae. dep 430

Yeast Ferments .. AE NOD MLO, ose Mane HOt: to ei Ure 431

Action of Cold on beenies 60. od 1) 432

On some appearances in the Blood of iventeinaned Unters with reference to the occurrence of Bacteria therein .. Part 4 525 Sexual Reproduction in Fungi .. +. 45 00 ene gg 594

Life-history of Aicidium bellidis D.C. Baer Peeper 595 Structure and Affinity of Spheria inocu CHNHA 0, BD tan, be 595 Spheroplea .. .. Bot DDS Godin hb aebe mice UB 595 New Parasite on the Silver Pir aoe Rca caan ties 995 Micrococcus prodigiosus within the Shell Ge an Ths Be, AG eae 596 Photogenous Micrococcus ws) © os ee gp 096

Respiration of Saccharomyces .. .» «1 «ss se is 9 596 eens OF GROKIRB 30 00 209000 xe 3 d96

Virus of Anthraz.. .. apes 9 598 Attenuation of Vir us in (Cutivations be Garner eed

DERG ere See Ni aibgemron aimee! Iran se Man) Mea na nok eneliaaes 999 IBOWB 55 a0 stslles Cathay atin awit ss 55 600 Bacteria in Canals ana Chines Saf NGL CWE) SROMAT AEM ST > igs 600 Bacteria from Coloured Fishes’ Eggs .. .. 1. +» «+ 55 601

Bacteria connected genetically with Algw .. 1. 44 +e 5 601 Action of Oxygen on Low Organisms..© .. 1. «0. «455 603

Biology of the Myxomycetes 00 56 603 Supposed a and Disengagement 71 Mitr hen aay

LEGA a0 00 regs oo oo dete by 7S Fungus Parasitic on Dr deanna sina baslyshol i cialis tone Ue dete nnee ema 783 WACONOS PORE, acon vema re cebel CNL eee. seo ae ube seat aes 3 783 Vine Mildew... .. sph (peje tole aS RVeRe ok loka a tfak ees aattees aS 783 New Theory of Henmientation Anphedat Money Luda eG a 784 Microbes in Human Saliva .. 6. ~.. 1. 2 «2 «1 gy 784 SMGIRGENE OFF HUMUR oo do. 40 ao 631-8065 bo 00 x 786 AGRE? Of © AHORWMD”’o5 00 60 0000'S 00s, 35 786 JROGHS Of WOE 00 5086 00g 786 JRO oo op SE CM Co era deOoe ere eens 787 Etiology of TiabeneHots oo Ae ere a cE er, 7187 Bacteria and Minute Alge on Papet fone eae. Yon \ Taeenu en 787 Grove’s Synopsis of the Bacteria and Yeast Fungi .. .. 4, 7187 Protochytrium Spirogyre, a New Myxomycete (?) .. . 788 Description and Life-history of a New ge Milowia

IUUDC Cm Clalaite PNGB) Surtees) eet -len lee) ue ype altGn S450 JOYCE JHURG 25 05 60 60. on 40 00 00 op 925 Parasitic Hymenomycetes ..- .. sel luaas ena oie te 925 Mode of Bursting of the Asci in the Sor tant (QB oo \ac- | oo 926 Actinomyces... .. Ao TN has ea riceas 926 Rhizomyxa, a vee Ph meee Pty 3 3 927

Effect of Light on the Cell-division of Chacon OMYCES.. -- 55 928 Behaviour of Blood-corpuscles to Pathogenouws Micro- RIOTS 56 lt b6 | oo Ge obtilaeas Iho. ol) 6000) sp 928

XXIV

CONTENTS.

Micrococei of Pneumonia .. ac

Micro-orgunism of Zoogleic Tuber Act ac

Microbe of Typhoid Fever of Man

Bacillus of Cholera and its Culture 5

Influence of Culture Fluids and Medicinal Recent on the Growth and Development of Bacillus Tuberculosis ..

Chemical Properties of Bacillus subtilis .

Supposed Identity of Hay Bacteria and those of Cattle Dis. temper oo . 0 4G) een 0

Bacterioidomonas sporifer. eye

Rabenhorst’s Cryptogamie Flora of aanan (Fungi)

Worthington Smith on Diseases of Field and Garden Crops..- Noy tetera san ke WN eye

Myxomycetes with Poeuto-plasmotia 20

“* Sewage Fungus” 4 bp. 90

Lichenes.

Cephalodia of Lichens ..

Lichens from the Philippines

Cephalodia of Lichens ..

Thallus of Lecanora Hypnum

Substratum of Lichens .

Hymenolichenes .. . bore Dara ete Relations of Lichens to the Ntheostee €

Alge. Symbiosis of Alye and Animals... .. . Relationship of the Flagellata to Alge and Taflsoria ia Transformation of Flagellata into Alga-like Organisms .. Protoplasmic Continuity in the Floridee .. .. Distribution of Alga in the Bay u Naples... Alge of Bohemia .. 50 3 Fossil Alga New Genera of Alje 0 Polymorphism of the Phijcochvomacen: Reproduction of Ulva .. 40 20 Relationship between Cladophora an Rhieocloniuin 00 Classification of Confervoideee =: Action of Tannin on Fresh-water Alga New Species of Bulbochate .. New Genus of Oscillariee -.. Vaucherie of Montevideo Gongrosira E Phyllosiphon Arisari

Occurrence of Crystals of Gy ypsum in He Despre

List of Desmidiee found in gatherings made in the neighbour- hood of Lake Windermere during 1883. ec! VY. ik 4-7) :

On the For riton eh Cane f Cells mn Tee genus ron y- siphonia. (Plate VI.) roads ‘

PAGE . Part 6 929 $i 929

3 930

= 930

ay ag32

ss 933

53 933

a 934

a 935

a 935

e 935

" 937

. Part 1 100 eer Be ON . Part 4 604 mis |S 605 ap lenny) 7S) Wen is 790 . Part 6 936 5 letie il Se 99 68

9 69 tor R102

= toe

‘ 102

a 102 aos

Jo" 105

5 106

» 106

- 106

Pe 107

= 107

se eel OT,

z5 107

5 108

55 108

. Part 2 192

CONTENTS.

Rabenhorst’s Cryptogamic Flora z Germany (Alg@).. Distribution of Seaweeds .. . 6 BOUL. emo. .a0

Cystoseire of the ee zi mee BORER 0 ENO.! Loo wt Polysiphonia ., «» oc Pe

LOO OCOD o0° 05. Ngai do. a0 00 06” 00 G0 Resting-spores of Mie SOMA OO ab k e0G, a0

Hybridism in the Conjugate eer

New Genera of Chroococcacee and eaveleee 50-90

Chroolepus umbrinum .. :

Constant Production of Oxygen th Yy ie Action of Sunlight on Protococcus pluvialis .. .. oH 90 oo! 90

Chromatophores of Marine Diatoms

Division of Synedra Una

Arctic Diatoms

Pelagic Diatoms of the Baltic

Diatoms of Lake Bracciano .. ob Gbb

On Certain Filaments observed in Surirella ifhons: (Figs. 49 and 50)

Bacteria and ieerasear steel re on We sosfinae of “Coins in currency

Fertilization of Cutleria

Endoclonium polymorphum..

Godlewskia, anew Genus of Cr ptoplucen a

Sexuality in Zygnemacee .. .. un ws

Movements of the Oscillariee

Alveoli of Diatoms

Researches on the Str settee oi the Gelanalle of Diners (Plates VIIT. and IX.) . oe seni Pesce ct

Systematic Position of Wilenene GCN, OTN Ede ak. /DOCEN Ci

Newly found Antheridia of Floridee

New Unicellular Alge .. :

Structure of Diatoms

Belgian Diatoms ..

Diatomacee from the ela of Saati, a

Researches on the Structure of the Cell-walls a Dialers (continued). (Plates [X., X., and XI, and Fig. 119) ..

Bacteria and Minute Alge on Paper Money

Fresh-water Pheospore od .

MOSHE co co 00 on. oc New Chromophyton ..

Wolle’s Desmids of the United Sis. Of

New Diatoms—Diatoms from Stomachs of apenas Oysters oe

Structure of bistons Ee

Researches on the Structure of the Gieaeds of Tete — Eupodiscus (Fig. 144) :

On some Photographs a Broken Danton ation taken by Lamplight .. Aen Sates | iakiige cia Stes

Algae of the Red Sea

Afghanistan Alge

Conjugate

. Part 2

Part 5

-. Part 6

XXKV

PAGE 270 270 271 271 271 272 2738 273 273

273 274 275 277 277 217

352

XXV1

CONTENTS.

PAGE Floating Rioularice .. 4. 15 06 ee we nee Part 6 937 [Spohacel rir ve atee new es ene ieso Proce T- 937 “ Sewage Fungus” .. aC Aimee nC Cue Ose Fp 937 Growth of the Thallus of Ontos sation scapes 06 937

Influence of Gravitation on the Movements of Onennae domonas and Euglena .. se +e ee we we we gy 938 Chytridiacee .. .. (gta ee eer Maret” Melani Ica Mtscon ate) STs 938 Cooke’s Fresh-water Vite lel es TNR Se Wels ss 939 Alge in Solutions of Magnesia and of apa Soke aD eee 939 Confusion between Species of Grammatophora .. +1 « 9 939 Depth at which Marine Diatoms can euist.. 1. +1 «5 45 939 Diatoms of Franz-Josef’s Land... .. 66) 00 940 Structure of Diatoms from Jens sf Cenenk Stone” at ely 940

Structure of the Diatom Shell 4. se ae ee wee 3 943

MICROSCOPY. a. Instruments, Accessories, &c. On the Mode of Vision with ancuge v Wide Aperture

(Figs. 1-7) «. - . 5 oo oo oo Jemde il AD “ Giant Electric Miieroseonee: ae i 109 Aylward’s Rotating and Swinging Tail-picce Microscope

(Fig. 8) Bee Or fe Ao a McLaren's Microscope, ne ‘Ring Foot (Fig. 9). fs 111

‘chieck’s Revolver School and Drawing-room Microscope.—

Winter’s and Harris’s Revolver Microscopes (Figs. 10 a and Band 11) . Jat Mea ieee: ly 112 Winkel’s large iDreenton Apion ane (Fig. 12) Wie a 5 115

Jung’s New Drawing Apparatus (Embr ae us fens powers (Figs. 13 and 14).. 3 9 116 Zeiss’s Micrometer Eye-picce (Fig. 15) .. Ne oer 7 118 Bulloch’s Objective Attachment (Figs. 16 and 1) a 118 Abbe’s Cameru Lucida (fig. 18).. .. .. . BE Wi aa 119 Millar’s Multiple Stage-plate (Fig. 19) a 120 Stewart’s Safety Stage-plate (Fig. 20) bid hee Nica 120 Parsons’ Current Slide (Figs. 21 and22) .. .. 1. 2. yy 121

Stokes’s Growing Cell (Fig. 23) .. ss. SUS Mee Oi oo 122 Nunn’s Pillar and other Slides .. .. ee 123 Beck's Condenser with two Diaphraym Plates (i. 2) 9% 124 Nelson’s Microscope Lamp (Fig. 25) . panne! : [OD 125 Developing Photo-micrographs 3 126 , Action of a Diamond in Ruling Lines upon 2 Giles 5 126 Test Diatoms in Phosphorus and Monobromide a ae

URE 10 9 Beer shttieny 138 Microscopic Test- Objects (Fig. 26) Sh eulets Brae tie 139 Resolution of Amphipleura pellucida by Central Light. Pr 143

Bausch and Lomb Optical Co.’s “ Investiy ee Impr oved” ;

Microscope Bn Pon a aoe: ‘5 144 Stage Condenser for Datanmee., “ 144 Bicentenary of Bacteria 144 Drawing from the Microscope < 145

CONTENTS,

Microscopists at Dinner

Photographing Microscopic Objects

Simple Eye-piece Indicator ..

Drawing from the Microscope

Dr. Holmes and the Microscope ..

Fakir and his little Fakes .. ..

Astigmatic Eye-piece Aud Moreh Sita en rare Simple Revolving Table.. .. yah Seven le Microscope in Medical Gynecol Olan ers

Fasoldt’s Micrometer. .. 1. «2 ae

The President’s Address

Ahrens’s Erecting Microscope (Fig. 28 )

Bulloch’s Improved “ Biological’? Microscope

Cox’s Microscope mith Concentric Movements (Fig. 29) Geneva Company’s UB aroaeise (Figs. 30 and aoe

“ Giant Electric Microscope” : : Tolles’s Student's Microscope (Fig. 32) ; Winter’s, Harris’s, or Rubergall’s Revolver iRaneseaine Geneva Co.’s Nose-piece Adapters (Fig. 33) Zentmayer’s Nose-piece (Fig. 34)

Térnebohm’s Universal Stage Indicator

Stokes’s Fish-trough (Figs. 35 and 36)

Nelson-Mayall Lamp (Fig. 37) ..

Standard Micrometer Scale

Microscopic Test-Objects (Figs. 38 eel 39)

Aperture and Resolution (Figs. 40 and i.

The Future of the Microscope 50-00 7 100 Webt’s “‘ Optics without Mathematics” .. .. Bulloch’s Nose-piece . os

Karop’s Table for Microscopical Poy, ean 20

Drawing with the Microscope .. ..

Substitute for a eae Table ..

“ Congress NOeseeaeD on “ Microscopists” and the poston ai the Micr aecaine so Revolving Table .. .. . eye on BC Penny’s Proposed uence 20 *o

New Fluid of great specific gravity, tan ge atte of refines:

tion, and of great dispersion .. 5 00

XXVU

Part 1

On the Estimation of Aperture in the hercscope (Plate VI. T. ) Part 3

Note on the Proper Definition of the Amplifying Power v

a Lens or Lens-system (Fig. 48)

Hensoldt?s and Schmidt's simplified Reading Memoscorees Pe

Geneva Co.'s Travelling Microscope (Figs. 51 and 52)

Reichert?'s Microscope with modified Abbe Condenser

(Figs. 58 and 54) .. .. . oe Reichert’s Polarization Weeeercoe (Fig. 55)

Reinke’s Microscope for pee the Growth of leans

(Fig. 56) 66) 00 Tetlow’s Toilet-bottle Micr ance (Fig. 57) Grifith’s Multiple Eye-piece (Fig. a Francotte’s Camera Lucida... ..

PAGE 145 145 146 146 146 146 146 147 147 148 173 278 279 279 281 282 283 284 284 285 285 286 286 287 288 289 291 300 300 301 301 302 302 302 302 302

303 337

348 436 437

437 410

441 442 443 444

XXVill

CONTENTS.

PAGE

Rogers’ New Eye-piece Micrometer .. .. « « «» Part3 445

Geneva Co.’s Nose-piece Adapters—Thury hope

Selection of a Series of Objectives BEA Acie

“ High-angled”” Objectives

Zeiss’s A* (Variable) Objective and “* Optical Tube longi 4 (fig. 59) . 50 Bare Le os

Queen’s Sani Mounting (Figs. 60- 62) . Boob h daly Loc

Paraboloid as an Illuminator for Homayencons immersion Objectives ..

Paraboloid for Ronating innate, m Lee, Fi igs. 63 and 64) erate 2s : .

Horizontal Position of the ne oscope 06. 6c

Flégel’s Dark Box (Fig. 65) Boh in

Feussner’s Polarizing Prism (Figs. 66- 73)

Abbe’s Analysing Eye-piece (Fig. 74) ..

Measurement of the Curvature of Lenses

New Microscopical Journals

Bausch and Lomb Optical Co.’s Tiencwsde ss Investigator”

Lantern Microscope i tieated: gee avers

Selection of Microscopes .. .. .. as

Homogeneous Immersion

Cementing Brass on Glass

Polarizer

Physiology of ispecies Vision with the Mi icroscope ore. 80- —2)

Dark-ground Illumination for showing Bacilli of Tubercle ..

Admission of Ladies as Fellows

On a New Form of Polarizing Prism (Figs. 87 ane $8

Microscope with Amplifiers (Fig. 89)

Bausch’s Binocular Microscope (Figs. 90 and 91)

Sohncke’s Microscope for Observing Newton's ae (Fig. 92) . Don 60

Harris and Son? s Portable Menoeccte Gas 93 an 94) .

Seibert’s No. 8 Microscope (Fig. 95) .

Reichert’s Large Dissecting aero and Hend Magnifier Ss (Figs. 96 and 97) 5 30 00

Geneva Co.’s Dissecting Micrgicdne (Fig. 98)

Drailim and Oliver’s Microscope Knife al ey

Ward’s Eye-shade (Fig. 100) es

Endomersion Objectives

Selection of a Series of Oigeuiees: :

Correction eee for Homo RAS ~ immersion Ob- jectives

Lighton’s Immersion Minirninaton (Fig. 101) P

Iilumination by Daylight and Artificial bien Morente and Lieberkiihns

Bausch’s New Condenser ( Figs. 102 and 103) .

Glass Frog-plate (Fig. 104) ot

Groves and Cash’s Frog-trough for ieoscanet nd Physiological Observations (Fig. aug

Visibility of Ruled Lines :

99

99

”

445 445 450

450 452

453

454 4595 455 456 462 462 463

463 464 464 465 4695 466 486 497 498-9

. Part 4 533

607 607

609 611 613

613 614 614 615 616 620

620 621

621 623 623

624 625

EE —

CONTENTS. XX1X PAGE Mercer’s Photo-micrographic Camera (Fig.106) .. .. Part 4 625 Photographing Bacillus tuberculosis .. 1. 4. «1 46 ys 627 Beck’s * Complete” Lamp (Fig. 107).. -. « ess 628 James’ * Aids to Practical Physiology’ DA Ghievaitey asta teary 35 629 Postal Microscopical Society. .. «1 su oe swe Sigg 630 Resolution of Anyphipleura .. 2 65 sa 6s «2» oe gy 631 Home-made Revolving Table OMRON OG. Bron it AG 55 631 SCLEGLLON OfspDLtCTOSCOPCSIs me iNae eae anne st- ict nce us 632 Wenham’s Button 00 SoM pete Ue Ge ea” es 633 On Drawing Prisms (Figs. 120- -2) Part 5 697 Albertott’s Micrometer Microscope (Fig. 123). : % 793 Baumann’s Callipers with Movable Microscope and Fined Micrometer (Figs. 124 and 125) «. 1s use Sg 794 Geneva Co.’s Microscope Callipers oe se aoMieteiie! 5s 796 Griffith’s Club Microscope 04 do 09 797 Nachet’s Class Microscope (Fig. 127). 9 797 Nachet’s Microscope with Large Field a 797 Stephenson’s Aquarium Microscope (Fig. 128) .. a 798 Swift and Son’s Oxyhydrogen Microscope (Fig. 129).. on 799 Nelson’s Hydrostatic Fine Adjustment (Figs. 130- Bie ape ery, 800 Griffith's Nose-piece (Fig. 133) .. .. «. od tp 801 Kellner Eye-piece with additional Lens as a Boinctatecre 0 801 Osborne’s Diatomescope ASR EPO Rae ey » 802 Hardy’s Collecting Bottle .. .. .. «. oe 0 803 Eye-piece Amplification 59 804 Illumination and Focusing in Photo- Linear eye) 5) 804 Mitchell’s Focusing Glass for Photo-micrography 5 805 Photo-micrography in Legal Cases (Fig. 134) A 806 American Society of Microscopists 99 808° Health Exhibition .. % £08 Objective Changers 5 809 Riihe’s Microscopical aie a eS 810 Microscope Tube-length AG lod deo" ac 5 811 Plane Mirror for Microscope Sisiblen tielae oA Sanda stone o 811 On some Photographs of Broken Diatoms taken by Lamplight SNM: = Bcras OG .. Part 6 853 Japanese Microscope (Fig. 145) . F 99 953 Schieck’s Corneal Microscope (Fig. 146) i op 954 Zeiss’s No. X, Microscope (Fig. 147) .. .. «2 os on 954 Wray’s Microscope Screen (Fig. 148) dono & eee oop 956 Abbe’s Micro-spectroscope (Figs. 149-151) >... «. 4. 5, 957 Eingelmann’s Micro-spectral Objective (Fig.152) .. .. 4, 958 Mayall’s <* Stepped” Diagonal Rackwork Ce 153-4) . 93 958 Fasoldt’s Nose-piece (Fig. 155) . ; 60 ai ‘3 959 Spencer’s Dust-protector for Onertine oF 959 Suift and Son’s Goniometer Stage (Fig. 156) 3 960 Hartnack’s Goniometer Stage (Fig. 157) .. 3 960 Osborne's Diatomescope (Fig. 158) .. .. swe 39 961 Wallich’s Condenser (Fig. 159) .. e 963 Cells for Minute Organisms... .. oo «1 99 963 Stokes’s Spark Apparatus (Fig. 160) . 33 964

XXX CONTENTS.

PAGE

Bertrand’s Polarizing Prism... 8 ae earl 6 3965 Electric Illumination for neta: Mick oscopical, and

Spectroscopical Work .. .. ie 966 Clayton and Attout-Tailfer’s ircoesomutie Plates for Gein

micrography .. Acai AGL RSS Ch 969

Error in Photogr aptingh Blon-conpueeles ach Go <p 969

The Tolles- Wenham Aperture Controversy ee bie ences anes 970 Amphipleura pellucida resolved into “ Beads.” Nature of

the Strie of Diatoms 00 Goi MOOI bade, ues © AD 971 Making a Neutral-tint Camera i Raa: Ean ee ee, Mee 7 974 ““ Which is the best Microscope?” We lea. Seasy, BOO Photographing Diatoms and Diffraction Gratings Sot als mss 975

Swift and Son’s new 1-in. Objective .. 1. «1 21 ++ 1455 976 Blackground Illumination .. 1. «1 se «6 oF «2 455 976 Cheap Microscope-holder .. : 976

Report of Deputation to the Wienicen Society) of Micro O- scopists and the American Association for the Advance-

ment of Science 3 MEE een aee thins inca Soyo 995 Death of Dr. J. J. Wooweard 00 0 90 997 Cheyne’s Biological Laboratory at the Health enniaen.. ,», 1000

Wright’s Lantern Microscope .. .. o. oF « «+ vy 1006

8. Collecting, Mounting and Examining Objects, &c. The Constituents of Sewage in the Mud of the Thames

(Plates I-IV.) .. . - Partl 1 Mounting and Pistownanting Ghote of “Centr a nents

System of Reptiles and Batrachians .. «1 «2 « 45 149 Preparing Spermatozoa of the Newt .. 0 150

Killing Hydroid eae and ms with the Tentacles

extended .. .. ide ue Bh ihotng Othe hes 151 Mounting Pollen as an “Opanite Object. jiiee Doe Book OOe Sap 152 Mounting Hiuid for Alg@ :- 3. 26 ws we weg 153 Mounting Diatoms in Series 60. 00 ¥ 153 Registering Micrometer Screw to the Ii araee WRectionns

(igs ZWD) co 0000 SOO ae omuci.A Ceigdiock op 153

Mounting Fatomslonieal Slides 00 154 Sets of Sections of Woods for psi rain m nab. no 9p 155

Staining Bacillus Tuberculosis 30-00, do SoC 155 Cutting Glass Circles .. .. . is diel gais, ues 156 Examination of Seminal Stains on 2 Cloth sis) Uye'a} J) colo: gelatin 156 Preservation of Museum oe Gat! BONE pee 60. gp 157 Glycerine Mounting SO neaain AacG)| macie uate 157 Peticolas’ New Slides of Deaton es cibich dee eget cue aera 158 Improved Slide Box seen: 158 Thymol as a Polariscopic Object .. 3 158

Stanley’s Standard Sections for Students .. .. .. « 55 159 Polariscope Objects .. . 00 159 Unpressed Mounting of the Fee eaee ae the Maro: Hy Aca ee ieee 160 Cutting Sections of Diatoms ap” ds 166 Dip Hie LAARGRUS OOPEFUBO 20 50 60 00 Bat 2 186

OONTENTS. XXX1

PAGE Preparing and Mounting Sections of Teeth and Bone.. .. Part 2 304 Expanding the Blow-fly’s Tongue .. oO 304 Perchloride of Iron as a Reagent for Pr Asoeitind Deiter Werrtn@. AHR gn 0g 00 oon 305 ACHiON Ofe Lani ON iUfUSOa) | eter ace nteennn es a 305 Preparing Fresh-water Rhizopoda .. .. .. «. «ss 4 306 Alpromgngy IDUOMS 25 60400 00 30 00 oc 40) 307 Mounting Diatoms in Series... .. i 308

Synoptical Preparation of Pinon Ones (Ginter from Guano, Fossil Earths, fc.) (Fig.42) .. .. «2 4, 308

SLOG ORG! SMOG) .co 00 0g, ih 310 Staining with Hematoxylin.. .. .. .» « «ss « 45 311 Dry Lea Masses .. .. Sar PAP nbn 2 eAttor Marit eee 312 Schering’s Celloidin for Teena or a, Wo aparin’ Sanam 313 Gage’s Imbedding-Mass Coo Pig. 43) on on ont 314 Gage and Smith’s Section Flattener (Fig. 44) .. .. «1 4, 314 Francotte’s Section Flattener (Fig. 45) .. 6. usw gy 315 Employment of the Freezing Method in Histology .. .. 4 316 Improved Method of Using the Freezing Microtome .. .. —4y 316 Mayer’s Method of Fixing Sections .. .. .. 1. .« gy 317 Gum and Syrup Preserving Fluid.. .. . 50 Ong 318 Cutting Tissues Soaked in Gum and Syrup uM bf Sane (55 318 Gum Styraz as a Medium for Mounting Diatoms .. .. 4, 318 Mounting Medium of High Refractive Indemn .. .. .. yy 319 Kingsley’s Cabinet for Slides (Fig.46) .. 1. «6 yy 320 Pilisbury’s Slide Cabinet (Fig. 47) .. .. 6a. 00 gp 320 Examining the Heads of Insects, ce te aise Bor whee en 321 Examining Meat for Trichine .. . eae inna GHe a 321 Jeans Iban CRYSIS 00 00 00 00 ah 40 09 322 Cole’s Studies in Microscopical Serene LCase urs Rumr oun oes 322 Pr EE) AMSOUTH AUN 0 3p on a gp 323 Browne’s Case for Objects .. .. 0 | gg 323 Fastening Insects and other small ris for CDsection AO. haee 823 Shidelof Raphides) from) Dapods- as sce) )s-p ose eeeen nee ss 324 Crimson Lake for Opaque Mounts .. .. .. 1 «ws gy 324 | Cosmoline for Mounting Starches.. .. .. 6. 46 ve 45 324 Hydrate of Chloral for Mounting ahs [ogee caer tA choy eS 324 Method for Double Injections .. .. ... 1. « yy 325 New Modification of a Turntable reap ereus amy viementam es 326 Bécker’s Freezing Microtome .. . fo 90 gy 333 Microscopical Society of Ladies at San rane a0) 1 aol ach 334 Dissection of Aphides .. ». 0 00 00 no JE aS Transmission, Preservation, and Mounting of Wprades 2) og 467 Breckenfeld’s Method of Mounting Hydra .. .. .. .. 4 470 OAS OAIRIGTES 36 60° Go) ee ron on. nopte ee Teen ep 470 Staining for Microscopic Purposes .. » 470 Mode of Announcing New Methods of aguathan ane Staining sp 471 Pure Carminic Acid for Staining.. .. «. >) 471 Hoyer’s Picro-Carmine, Carmine Slt, an Ger mine

I ROUAP IO IAORED. 00, “a Mba Bn sBcl aR ne od) py 474

Dry, Ti ection Masses mn pae einer aigoe iss issn) bess aca. as 474

XXX1i

CONTENTS.

Imbedding Diatoms .. . aoe eel eae astm tate

Zentmayer’s New Centering Turn- table (Fig. 75) .. «

Phosphorus Mounts .. ode coche boraa-ote lb ati lieerio

Styrax .. o» BOs | hGOk. ocala cia mocieeano

Smith's New Mounting “Media Gi eee ticigliar Ome eeleinc

WSS Cel (88g6 TD) oo uo on nS SS

Closing Glycerine Cells. don irod | oa

Getschmann’s Arranged Diatoms..

Classification of Slides .. O06 Od) 00) GO oor! Joe

Blackham’s Object Bomes .. «1 «+ se se se a

Stillson’s Object Cabinet

Pillsbury’s (or Bradley’s) and Cole’ s Melng Cases gs TUT) 0000 50

How to send living none 50 Age oa fou Preserving Liquid for Anatomical Onjectsn Sei adyycon Blue Staining .. «. Si ihpr ial ecco hen dra Miedo eedoe ooo Crystals of Arsenic .. ., Sate let a eh How to Mount Casts .. «-

Mounting Desmids ATOMS Gee vente tele Meters

Staining Bacilli of Tubercle g0) Woo ‘oa 00

Measurement of Blood-corpuscles

Naphthaline .. ..

On a New Microtome (Figs. “93 ae 84)

Methods of Investigating Animal Cells

Born’s Method of Reconstructing ees om Mioascop ISECIIONS) se eel eel wie 20) 00

Shrinking back of T8296 of Oribatide in | Mounting

Preparing the Liver of the Crustacea ..

Preparing Alcyonaria.. ..

Semper’s method of Making Dried Pra seneRTS

Method of Detecting the Continuity a Pr ude: m Vegetable Structures

Method of Preparing ae iors eins ‘ae the Microscope a0 c Se Md areas

Chapman’s Microtome .. 0

Use of the Freezing Microtome .. io) hOnueOSh Odo

Apparatus for Injection—Fearnley’s Constant Pressure Apparatus (Figs. 108-18) 0

Myrtillus for Staining Animal and Vedeiane Tissue

Hartzell’s Method of Staining Bacillus Tuberculosis ..

Safranin Staining for Pathological Specimens .. .. .. Collodion as a Fixative for Sections Hora p0 LEO FOTROPS KEES on oS

Mounting in Balsam in Cells 0

Styrax, Liquidambar, Smith's and van Hepes Mean Groupiny Diatoms etn eee on dt : Quantitative Analysis of Minute oie) Dearmisns oo 0)./b9 Microscopical Evidence of the Antiquity of Articles of Stone Carbolic Acid and Cement for Algae .. .. «2 oe Catching Small Insects .. Boh fuinteehce

Mounting the Skin of a Silkworm

658

CONTENTS. XXX1il

PAGE Kidder’s Aeroscope se beliciewl) Moles Savi eee bela AMOR ses EArt 4s GOS Bubbles left in Fluid Mounts .. 2. sn ss wee Say 658 Clearing Fluid .. .. Hose Bot pc 659 Detection of Poisons and i carnination of Blood Stains .. Part 5 812 OURG JOfUSOTV co 0d 00 90 00 813 Perchloride of Iron .. os 813

Mounting of Hoan eatfon a= NO Slide for Onan Oyjecen » _ 813 Hematoxylin as a Reagent for Non- CS and Non-

suberized Cellulose Membranes.. .. 00-00 814 Canarine for Staining .. i 815 Cultivation of Bacteria upon Oh ‘Slide (Figs. 135 anh 136) will) Staining of Schizomycetes in Sections and Dry Preparations ,, 817 Staining Fluid for Sections of Tubercle-Bacilli .; .. 2 818 Methods of Imbedding (Figs. 137 and 138) bor eodn WOOm lea 818 Hofimann’s Imbedding Apparatus (Fig. 1389) .. .. .. 45 821 Celloidin for Imbedding .. aaaleron Wheteh ee ele) Llsa 822 Reichert’s Microtomes (Figs. 140 and my sen ot, Mee 823 Decker’s Section-smoother (Fig. 142) .. .. «1 ws we gy 825

Griffith’s Turn-table (Fig. 148) .. “ ere came tate Matattnen oobi | ay 826 - Reversible Mounts ae WR bceinei noche MISE Me ccrye ooa52 826 Hinman’s Device for Mounting SOME ome Hane ino ashi eg lr 827 Preparing Schultze’s Solution .. 1. 1. 4» 00 we gy 827 Syanirate Chol JOKeMMClnNOUP 65 60 00 60. 60. 0d” ov . 827 Jerguaring Soqlkie CARGNE oo 05 60° 00 bo 00 06 gp 828 Gouining) iueroms Wide SIBGP 60 50 66. 60 60 0p) 829 Lyon's Mailing Case... .. 5 829 Action of Reagents in the Danian of Veceraie LIRR bn 6 SRR Tne i mae abe se 829 Reagents for Feros a in s Went Coils Bbioda OO, 106. ogy 832 Microscopical Examination of Chestnut-meal .. .. 0» 5 832 Microscopical Investigation of Dyed Cotton Fabrics .. .. 45 833 Microscopical Examination of Water for Organic Im- FOUOIS Gon ea) eae Ned 60. 09.00 , 833 Changing the Water in | Anuar ‘eiainng Wierosecerent Organisms 00 00. 00 a0 oo 00 835 Micro-Chemical Test for SedRiox 90 60° 00 eo 00 836 Micro-Chemical Reaction of Solanine.. 1. .. «. 4 836 Size of Atoms .. so Gh. Cm DO eobe Brey 836 Liquid Films and Molecular Mematinreen 00 60" oo) on! & 837 Air-bubbles in Glycerine Cell-mounting send avent a et * 837 Thoma Microtome Gc. 1a) Libth Teaco Son, oe Panel meen 838 Smith’s Mounting Medium .. 2. 0. 1» os as ogg 839 Peirce’s Slides .. . 60 |) Ol | OC; moony Boni loon Meany 839 How to Harden Balsam “Mounts elie resets PA xerskeaetciowy aera. weleiaackrs 840 Mounting Fresh-water Alge ‘is Spa eae Wea a eT OaaT lec 840

Hardy’s Collecting Bottle (Fig. 161) | 66 00. 00 on ler Bez Collecting, Desi dstpme mares tamce ene) n eas) aes ae 977

Preparing Embryos .. .. a) 00 80d) 00.) op 978 Method of Studying. the Amphibian ae Brea ers AGN cys 978 Preparing Planarians and their Eggs.. .. .» «. 0 4 978 ISOC IGHCOHED HOES bo a ab Bah ea J add) Ac 8S ep 979

Ser. 2.—Vo.. IV. Cc

XXX1V CONTENTS.

PAGE Imbedding in Sticks of Paraffin .. 1. «. « « « Part 6 981 “ Microtomy” .. Sox) Nea ae a Goel icde @ Scie bare raat 981 Gray’s Ether Treen Mier Mare soc oe ase cons oul: ty 981

Preparing Picrocarmine and Indigo Gere Bier ters aokcays Laois 982 Mercer's Solid Watch-glass (Fig. 162) .. «2 «2 « 4 983

Cheap Method of making Absolute Alcohol .. P » 984 Arranging Sections and Diatoms in Series... «1 .. «+ 4 984. Balsam of Tolu for Mounting .. . 5 985 Biniodide of Mercury and Iodide of Dephessioiy aa Phos phorus for Mounting APEC ORE da ar OO Loree ute hy bas ash 985 Chapman’s Slide-Centerer .. .. sve ameic a eel aeaiiee as 986 Indian Ink for examining Mier aneainte Orgone : 986 Apparatus for Aerating Aquaria 30 55 988 Detection of Sewage Contamination by the use i ‘the ier 0- sccpe, and on the Purifying Action of Minute Animals and Plants Ae niges aie scat ornate PEA ie eet 988 Examination of H andionitieg Be OMY rad s\oun 1 oO = <ch 991 The Microscope in Paleontology Sih Ge AGAemGtus Sods ag ep 992 Easy Method of Staining Bacteria .. ss s «se « 455 992 Typical Series of Vegetable Fibres .. «6 «1 «ss gy 992 Identification of Blood-corpuscles a0 SAP SONE 15 993 Mounting Bugula avicularia with polypes emneraed aces ek hen 994 Miquel’s Sterilized Gelatinized Paper and Maddox's Col- lodion Films for propagating Bacilli .. .. » 1002 Proboscis of Blow-fly mounted in biniodide of mercury ane HOON) Of FUOWESWHOD 65 5. 6050 co 30 00 60 gy JMO BisLioGRAPHY—MICROSCOPY a 5 he eel Ant Soon eaten Nena opn leer dl Ise" p 00 » 2 300 5 ov rs : » 3 463 50 ae 36 00 » 4 630 on Ee j » » 809 » AON Ea EA Cin ac laacoe movmaninoe toc made nen, O STS WINER SY (55 “ho oo og Go so 0c no | on Jeep IL ieee 3p Bran WA Aulctaitdde MeO ll nod: do do", gy, 2a. Oe a 6 00. 60 60. 00 » 3 481 pt iraeo cco eae mae » 4 697 » 00° 60 ad ; » 9 837 BS . . boll = a00h Go » 6 992 PROCEEDINGS OF THE SOCIETY— Mecember A, WSS. yer we New) fs ae eee ae Joe ae ante hOt November 8, 1883 Camaneione).. rats Hcoadt AORN cIs RaGe ny Od, ne 163 January 9, 1884 : Preeioc wacom sage) ao! 165 February 13, 1884 sine Meeting) nga) foo. G0. bos oo LER) BUT Report of the Council for 1883 .. .. 6. «wee egg 329 Treasurer's Account for1883 .. .. .. .. «2 «of ow 455 330 Wikwyeloy 119%, WES oo oo) co) | to oe vod fag og) Gao 00 332 April 9, 1884 50 60 oe) ee eart3 486 May 14, 1884 (recall it | Ordinary Meetings) « mmc eme 5 499 June i, SS aerial 30 6 go. (od on | oo JERS Lat) October 8, 1884 Phe Uae. 5s ee eee eatLtOMooo Mavere® 1a ote) SO a ae a Mees dl act! ome “pyc LOOP

DNB see. nok ee gate eat aay athe US a is os I mer re CRD

“The J ournal is issued on the second Wednesday of ; / Rebruary, April, June, August, October, and December.

Vol. IV. Part 1. Price 5s.

: — Ser. II. \ FEBRU ARY, 1884. if Non-Fellows, 2

JOURNAL

Se Rovan - MICROSCOPICAL SOCIETY;

CONTAINING. TS TRANSACTIONS AND PROOEEDINGS,

AND A SUMMARY OF CURRENT Eales ACHES RELATING TO ZOOLOGY AND BOTANY. ‘(principally Invertebrata and Cryptogamia), _

MICROSCOPY, &c.

- Raited by

FRANK CRISP, LL.B., B. A, One of the Secretaries of the eas ? : and a Vice-Pr estdent and Treasurer of the Linnean Society of London ;

WITH THE ASSISTANCE OF THE PUBLICATION COMMITTEE AND

A. W.-BENNETT, M.A., BSe., F. JEFFREY BELL, M.A,, Recrirer on Botany at St. F isles ‘s ospital, Professor of Contparative Anatomy in King's College, 8. O. RIDLEY, M.A., of the British Museum, JOHN MAYALL, Juy., _anp FRANK E. BEDDARD, 11.A., : - FELLOWS OF THE. SOCIETY.

“WILLIAMS & NORGATE, LONDON AND EDINBURGH.

NTED BY WM. CLOWES AND SOMS, LIMITED,]. [STAMFORD STREBT AND CHARING- CROSS;

( Bye

JOURNAL

ROYAL MICROSCOPICAL SOCIETY.

Ser::2.-VopelV a eAR@T kk (FEBRUARY, 1884.)

i a ys: ac ‘ Be ;

ae

CONTENTS. —

eee 4

: 7 4

TRANSACTIONS oF THE SoormtTy— y PAGE) 9

-.—Taue Constrrvents or SEWAGE IN THE & Mop or THE THAMES. By mee Lionel §. Beale, E.R.S., Treas. R.M.S. (Plates I-IV.) — Bee eR a JI.—On tee Mopr or Vision WITH Onsuctives or WIDE AvrRrure, :

By Prof, E. Abbe, Hon. F.R.MLS. (Figs. 1-7)... 20 Summary or Current ReseARoHEs RELATING To ZooLocy AND Botany (PRINCIPALLY INVERTEBRATA AND Cryprogamta), Mroro-

_ BooPY, &c., INCLUDING ORIGINAL CoMMUNICATIONS FROM FELLows) AND OTE GO ak ae GRE an nO ea aaa UU oa NU Sle eee ag ee < z y

ZooLocy. : Influence of Gravity on Oell-Division te son eer ae Influence of . Physico-Chemicatl eee upon. the Development of the a Tadpoles of Rana esculenta .-.. sear et Oa Colowrs of Feathers .. SSP had eet wel pod Sree ptitto ah Cece Ty eats ee ae Rudimentary Sight apart from € yes Bre rete Bee atk wit ats Ree weed gly pig te reas Nerve-centres of Invertebrata... - A dN e re SRE ole alot UNM NY Shad on eb ‘ Tracks of Terrestrial and Fresh- Tanker Annals fay es Site Boee AE pet A ele Growth of Carapace of Crustacea and of Shell of Mollusca ei ctenc tyatel Nt vale) gees al Commensalism between a Fish and a Medusa... .. EB ae Rance ake ve Symbiosis of Algz and Animals j. 410 +s ess EG eae See 4

. Skin of Cephalopoda _.. Wels ah gee aes Ce iladh Seiaat aD ae

Development of Gills of Cephalopods Paliuiisalk wk twnush sue yehescan yore «oc a Blt su OLR ae Further Researches on Nudibranchs .. 0 1. 00 de ee ee ae ee OS a _. Functions of the Renal Sac of ‘Heteropods 1S er ee tt laa tae Hae aI ccna gop a Interstitial Connective Substance of Mollusca... .. =. se ue ae ee BD Visual, Organs in Salen < 00 ag ene eae), Setdl ve tiew. maak eu ve BO ae Respiratory Centre of Insects... patie etoh Taeioe wise eae Chordotonal Sense- -organs and the Hearing of Tisetts 03 oe 1S a Spine ae Number of Segments in the Head of Winged Insects... oe 2s ge ae 48 Protective Device employed by a pe abrpalae Pio apet Blak dope ah Oe BAe

Formation of Honeycomb .. +. Bites ere rac cig ite eS Mouth-Organs of Rhynchota - roe Nah ie eee ac Me ee al Development of Genital Organs a Insects .. PAPE OL POAT HN WERE NET Fe Genital Ducts of Insects: . de esta cron daee ear hese a Le Oe Thoracic Musculature of Insects. as CORRE ue aarebenc: sattiss fe og Early Developmental Stages of. Viviparous phi ROE ME py eae OL Cee Chlorophyll in Aphides .. Rae GH Cepense ri be Testis of Limulus...» a gl PMSA Seco mastaynt RG eR - Polymorphism of Sarcoptidee 43 Br, sea UO Sal sage cig a Re a Spermatogenesis of Podophthalmate Crustacea ee fivattabaah che its 7 oer co am American Isopoda 6 aS es oreo by Ne NE a ta OO a

New Host for Cirolana concharum Harger Fe CAN oe ee eee a ame Copepoda Entoparasitic on Compound Ascidians ..- 2. es ue ns Anatomy and Physiology of Sacculina 26 00 20 ee ee) de, oe oe BL Classification of the Phyllodoceide* .. 0-1. bv ee ae oe ae te we OB Anatory, of LOWNOUNG ss Fs OI ows apse anid vane each Goh ase) oa boa oe Spadell Martane oF ese aes ae ce iwc, ins: nets Wa se be bey ane Wamaon gD ee New Forms of Thalassema VPP PPE: SN Re react, See QRH MD WED Waban MenLaRuISNTE

Summary or Current Resnancues, &c.—coutinued.

{( 3 )

Structure of Helminthostuchys 2. 1. se vee ee ae

z PAGE Spermatogenesis in the Nemertinea .. ss oe ee we eet ewe OD Development of. Vrematod ie 4 cio eae 6s heh ooh > wo gee han ae? Aes OO Stimondsia parudoxa —.. SERRE ae acre ere, ener tree Sncte hie GOEL) Monograph of the WWcleser dis ace. HS A as Flistology of Hehinodermata 08 sg) hee hee aos Lew eke erm eet 60 Nerious Syatemof HOlOwwurians co: 0. Se Sy as hiee ye ek we oe 62 Vascular Systeme of Eichinpgerms: ays ws Ne aw cease ae alee as 08 Nervous Sistem Of BOvpitd es ae 1s as eee ha ied Vee win, me OF Berman Meduse iy ii7 ag on) ea oer Selle Pom ha Meme Noreen, eek east Od

Alleged new Type of Sponge SAL ee dere iN, Meeri ya Al Voraamaincr ss ccets 40K) Boology and, Anatomy Of, CHONG x6 2 he" Aa Sen taht Roe) pny Apel Cee unset OD New Silicious Sponges from the Gonte een Lee. ci marten Gal Rade 1as OO Parasitic Infusoria 2. .5 Se ONE sinieran My ne NP tia tenn Pantech g New Infusoria — .. Arai Ore eRe Sa Re ore gs Relationship of the Flagellata to ‘Alge “and “‘Infusoria Be GOR kg cea ae OS

-- Transformation of Flagellata tnto Alga-like Organisms .. %. +» .. «. 69 WLELINS UN USTONSENVETE® ah eee Pogo ane AM oe eh ieee ian cient! leureee oe 70.. Cilio-Flageliata _ .. Se oe eo coals UN Oat omen a aaron Ce rey a ete ahs New Choeno-F Flagéllata ip Aigo ic eala VN og UD eA Bate SRI eD PS Irate a ee dE Anatomy of Sticholonche zanclea Syl Svea ota Reap mae MON te ely eae ood DOUUES OTE TNE HOTOMMUNEP CLO © 2355 es aly dei aah ha Jiael nh lees ea ee AE Developimentof. SUMO ynehugs sya aa ahi- ae Gems inal coat) ES | eee eee UE

Borany.

Relations of Protoplasm and Celi-wall in the navies CEU ea Wide ag ive oO Intercellular Connection of Protoplasts 2. 6. se ee ee ee we 6 Polyembryony of Trifuliwm pratense .. 6. ewe ee ts eee SG Mechanical Structure of Pollen-grains ©... 2.) ee ue ee a wee TE Rertitization of .Philodendron™ se 00 0 es ey ea se ee ww ee TT Fertiiization of the Prickly Pear Tas BCE Me ee ORR Ren I Cee Annual Development of Bust .. .. LO et oes Th Lenticels and the mode of their replacement 4 im “some ‘woody tissues ea ate eS Gum-cells of Cereals... .. REE aE oe Cee aaa, SOS 9). enor coy 78 Nucleus in Amylaceous Wood-eells SEO go Uae Saat aa gin i UN dimen) EO Peculiar Stomata in Coniferee .. 06 oe ae ee ee ee ee TD Root-hairs SER MO IO TE SNE LDA OS ea eS Sieve-tubes of Ciera cea a eh Cee as es er sd Spines ofthe Awana cee sees Vos oP wa wee eel owe ie Ve eal ee OL Tubers of Myrmecodia echinata .. ve SL Chlorophyll-grains, their Chemical, Morphological, aha Biological Nature . 81 Mechanism of the Splitting of Leguines ae 82 Acrial Vegetative Organs of Or chidee tH relation to their Habitat and

"Climate .. 83 Assimilation of Carbonic ‘Acid. ky “Protoplasm which does not contain

Chlorophyll... Pen eee ain eng eros OD Artificial Influences on Internal Causes of Growth . Deine ety tre areaAreaael eg ce SD Absorption of Feod by the Leaves of Drosera 2s 6. ue tsa te we 8B Mechanical Action of Light on Plants - : 84 Action of the Amount of Heat and of Maximum Temperature on the Opening of Flowers -.. Beat ea ay Shara eg eee eer OO Behaviour. of Vegetable ones Footie Gases Gerke ues ea een

_ Influence of External Pressure on the Absorption of Water by “Roots 85 Contrivances for the Hrect. Habit of Plants, and Tee of iy ey: ‘ration -on the Absorption of Water... 4. ss os we A Beste <0 )) Sap a Wet Sse le oa ae a as Be RON aotas eee ae eR OO, Solid Pigments in the Cell-sap Bet alg Snipe de iets thpie lode ewe Cag ON Movement of Sap in Plants in the Tropics Ee A ete nes tate ceria Bry aay eee f Huudation from Flowers in Relation to Honey dein. a eee 87 Latex of the Kuphorbiacee .. ee el seimiceaet sts Crysialioids in Trophoplasts, and ‘Chromoplasts of Angiospern ms... 89

Formation and Resorption of Cystoliths .. a 90 Function.of Organic Acids in Plants _. eh cwee nec buses 100 Formation of Ferments in the Cells of Higher SORTA OLS sen SOOM Ge Poulsen’s Botanical Micro-Chemastry:. .. 0 ise se ee ve ae we we Classification: of: Opiioglossaced 26 sc eras. Sea Cae zee ee ee an 2 OF

Rau rrors be

C249)

Summary or Current RESEARCHES, &c.—continued.

PAGE Structure and Development of certain Spores .. +» 4 es ee ee as 9B Alkaloids and other Substances extracted, Jom “Fungi ela g oo eae ea Pe ee Developmemt of Ascomycetes 1s ve thie et aay ner oi sm ou tt eamiearaass Aen Conidia of Peronospora .. «+ «0 se ee ee oe te ete nD Pleospora herbarwm 1. s+ | ae be oe te ett ee ewe wD Chytridiacez On ee oe oo eo eo oe &e . 96 Phoma Gentian, a new Parasitic Fungus ES Me teas CS > 96 Chrysomyxa albida 2. +» ae ee eee tee Rees 96 Physoderma .. <e0 on be. ue Nee ne ee 7 ee oe eee 97 Bacillt of Wiiberchs Pian tee dg Vea ewes cae ot Den icone ree : Sess Microbia of Marine Fish .. deny Sees es . 98 Physiology and Heep ay of Atoohotie Ferment. Bec Sal eos SOS

Alcoholic Ferments .. 3 Sen ee Siac te eo Maghin's © Bacteria? iis ceo te ser eh te ek ee ee aw OO Cephalodia of Lichens Beak ENT aoa ib ge aot eigen cae cei Neary nee Soe oa 1 Aaa Lichens from the Philippines «. aR arash Tas sein Pe ee day Sean SLO: Protoplasmie Continuity in the poner GSMS Sear esse on a ctwigs Sen ae LON Distribution of Alyx-in the Bay of Nook ‘ Pi ‘:

Algz of Bohemia = «1 as weve sees See one Fosstl Alga) v0 is 2) one pons ge fae) ee, tans uke ea oan ae as sey AOR New Genera of Algzw .. ss oe Faas ree one ae eS

Polymorphism Git ihe Pliycochromaces Perce cee ae cimeate om ena! ana see OD Reproduction of Ul Vert ptenc test wees ten = LOD Relationship seen {Clalophora: and Rhizoeonivm SebmmenC errant cal (lsh Classification of Confervoider .. «2 « Or Seer erio anon messes: ACI

Action of Tannin on Fresh-water Alge 2. se 20 ee ne we ws we 106 New Species of Bulbochate = 1. ee se ee ae we te te wn 107

~ New Genus of Oscillariew 1. 2+ ae ee we oe we ee we ewe LOT Vaucherix of Montevideo .. s¢ 2+ os en oe ee ae we we we 107

Gongrosira .. SoU Maley ces Cum nea Ue Gua ania Obey siete are Wen oan mewn

Phyllosiphon Arisari .. yy a tees Sew ue Reine LO pear of Crystals of Gypsum in the Desmidien .: 0. wes ve 108). Mioroscopy. co.

“ Giant Electric Microscope” ose 109

Aylward’s Rotating and Sins Tail-piece Microscope (Fig. 8) Bee oer LEO.

McLaren’s Microscope with Rotating Foot (Fig.9) -.. .- lll

Schieck’s Revolver School and Drawing-room Microscope. Winter’ s and Harris's Revolver Microscopes (Figs. 10 Aand B).. .. .. .. « J12

Winkel’s Large Drawing Apparatus (Fig. 12) 5 115. Jung's New Drawing Sees (Eimbr, yograph) for Low Powers igs. 1 13 and: 14).. ~ 116 Zeiss’ s Micrometer By "ye-piece (Fig. 15) 5 ig ieee ea taten AOR ELO Bulloch’s Objective Attachment (Figs. 16 and 17) « Saget eee oe LES Abbe’s Camera Lucida (Fig. 18) . Re AS aarti aren re ae gerry peal SF

Millar’s Multiple Stage-plate (Fig. 19) Se ae SE OR ic een Stewart's Safety Stage-plate (Fig. 20) .. ss 4. se te ue ae ee «120 Parsons’ Current-Slide (Figs. 21 and — Se eC ny cea ed - Stokes’s Growing-cell (Fig. 23)... nat sganliu ee te ee gaiCe ce tami 1a os ae

Nunn’s Pillar and other Slides... -. ote ee ete Beck's Condenser with two Diaplragm-plates Cig, 2) SEES, Oe OM a Nelson’s Microscope Lamp (Fig. 25) ie ARE SS ee OR aa Developing Photo-micrographs .. +s. Ba, gat uses Solara Sele oe ines) ema Action of a Diamond in Ruling Lines upon Glass. 3. Se Lee Test-Diatoms in Phosphorus and Monobromide of Naphthaline ema eas ice Microscopic Test-Objects (Fig. 26) . it rea G2 Wie PRG sa Resolution of Amphipleura pellucida. by ] Central Light... me 143°

Mounting and Photographing Sections oe eo Nervous ‘System of Reptiles and Batrachians .. .. Preparing Spermatozoa of the Newt —.. Killing Hydroid Zoophytes and Polyzoa with the Tentacles evtended Mounting Pollen as an Opaque ae Mounting Fluid for Alge .. .. «. _ Mounting Diatoms in Sertes.. Registering Micrometer-serew to the Thoma Mier otome (Fig. 27).

oe

PROCEEDINGS OF THE Socrery 0

Cb) ROYAL MICROSCOPICAL SOCIETY.

COUNCIL.

ELECTED 14th FEBRUARY, 1883.

PRESIDENT, ~— Pror. P. Martin Dunoan, M.B., F.RB.S.

: VICE-PRESIDENTS. Ropert Brarrawaits, Esq., M.D., MRCS, F.LS. . James GuaisHer, Esq., F.R.S., F.R.AS. Cuartus Srewart, Esq., M.R.CS., F.LS.

: TREASURER. Lionen §. Bratz, Esq., M.B, F.RCP., FBS.

SECRETARIES. Faas Crisp, Esq., LL.B., B.A., V.P. & Treas. LS. Pror. F. Jerrrey Bett, M.A., F.ZS.

_ Twelve other MEMBERS of COUNCIL. Joun Antuony, Esq., M.D., F.R.C.P.L. AuFRED WituIAM Bennett, Esq., M.A., B.Sc., F.LS. Wiuiram Joun Gray, Hsq., M.D.

J. Wittiam Groves, Esq.

A. DE Souza Guimarazns, Esq.

Joun HE, Inepen, Esq.

Joux Marrurws, Esq., M.D.

Joun Maya, Esq., Jun.

Apert D, Micuarn, Esq., F.L.S.

JoHN Mizar, Esq., L.R.C.P.Edin., ELS. Wittiam Tromas Surroix, Esq. Freprerick H. Warp, Esq., M.R.C.S.

LIBRARIAN and ASSISTANT SECRETARY. Mr. James West.

| The “ Aprrrure” of an optical jnstrument indicates its greater or less capacity for receiving rays from the object and age, and the aperture of a Microscope objective is therefore determined by the ratiu ~ the diameter of the emergent peneil at the plane of its emergence—that is, the utilized ~

transmitting them to the im between its focal length aud

(

6)

I. Numerical Aperture Table.

diameter: of a single-lens objective or of the back lens of a compound objective,

This ratio is expressed for all media and in all cases by m sin u, 2 being the refractive index of the medium and w the — semi-angie of aperture. The value of m sin w for any particular case is the “numerical aperture” of the objective. © z}

Diameters of the Back Lenses of various Dry and Immersion Objectives of the same Power G in.)

_- from 0°50 to: i752 N A.

ee

© © © ©) 2

(

ee

numerical apertures.

I-52 AO sepa es

Numerical Averture.

———

° « . ° . ° ° e . . ° .

00.

1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 i 1 1 0 0-98 ) 0 ) 0 ) G ) tr) tr) 0 ) tf) Oo ry Q 0 0 ) ) re) ) 0 0

Angle of Aperture (= 2 u).

) Dry (m sin-w = a.) | ‘Objectives.’ @=T,

9s° 95° 92° 88° 85°

82°

79° THe 73°

70°

68° 65° 62°

60°

‘| 92° 24

Water- Immersion} Objectives.

(1% = 1733,)}

100° 10°

97° 31" |

94° 56’

89° 56’ 87° 32'! 85° 10") 82° 51’

80° 34’)

78° 20’ 76°. 8’ 73° 58’ T1949" 69° 42° 67° 36° 65° 32! 68° 31’ 61° 30!

59° 30’ 57° 381’ 55° 84! 5B° 38’ 51° 427) ~49° 487) 47° 54!

46° 2!

Theoretical Resolving ~

Power, in

=liné B.)

146,528 144,600 142,672 140,744 138, 816 136, 888 134,960

131,104 129,176 128,212

125,320 123,392 121,464 119,536

117,608 115,680 113, 752 111,824

- 109,896 107,968

106,040 104,112 102, 184 100,256

98, 328 96, 400 94,472 92, 544 90,616 88, 688 86,760 84, 832 82,904 80,976 79,048 77,120 75,192 73,264 71,336 69, 408

- 65,552 63, 624

59,768

! Tilumi- Homogeneous-| nating Immersion | Power. Objectives. | .(a2.)

(t= 1°52.) : ie 180° 0’ '2°310 161° 23" | 2-250 143° 39" | 2-190 147° 42" | 2-132 142° 40’ 2-074 138° 12’ | 2:016 134° 10’ 1:960 130° 26’. 1-904 126° 57’ 1-850 123° 40’ | 1-796 122° 6! |1-770 120° 33 '1-742 117° 34’ 1-690 114° 44’ | 1-638 111° 59’ | 1-588 109° 20' |1:538 106° 45’ | 1-488 104° 15’ | 1°440 101° 50’ | 1-392 99°, 29’ | 1°346. 97° 11’ | 1°300 94° 56’. 1-254 92° 43 | 1-210 90° 33% | 1-166 Sse v6! | 1-124 86° 21’ | 1-082 84° 18’ | 1-040 $2° 17 | 1-000 80° 17’ | +960 78°. 20" | +929 76° 24’ | +884 74° 30" | +846 72° 36' |. 810} 70° 44’ | +774 68° 54’ | +740 - 67° 6! -706 65° 18’ | +672 63° Bl’ | +640 61° 45’ | -608 60° 0’ | “578 58° 16’ | 548 562 32’) -518 54° 50’ | -490 53° 9" | 462 51° 28’ | +436 49° 48’ | +410 48° 9’ | +384 46° 30° | -360 44° 51’ | +336 43° 14 | +314 41° 37" | +299 40° 0’ | +270 88° 24’ | +250

55,912 53,984 52,056

50,128

48 200

| Lines to.an Inch; (A=0°5269 w

133,032 -

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TRANSACTIONS OF THE SOCIETY.

So

I.—The Constituents of Sewage in the Mud of the Thames. By Lionet 8. Bratz, F.R.S., Treas. R.M.S.

(Read 10th January, 1884.) Puates I.-IV.

Tue particles constituting the cloud-like masses of dark-brown and in some places black mud, held in suspension in the tidal water of the Thames and carried backwards and forwards by the tide, and which subside and form the soft mud which accumulates on the surface of the submerged banks, have always afforded objects of

EXPLANATION OF PLATES I.-IV.

Puate [.

Fig. 1.—Objects in Mud from Crossness Southern Outfall.a, muscular fibres which have passed through the intestine and have been partly dissolved by the digestive fluids, but which have undergone further disintegrative changes in con- sequence of the prolonged action of the Thames water upon them. In many of the muscular fibres the tranverse markings are still visible. Ata** is seen a fibre in which the transverse striz are very distinct, although the tissue is itself undergoing disintegration. c*,a portion of a very small spiral fibre from vegetable tissue. d, crystals of fatty acids formed by the decomposition and oxidation of fatty matter. d*, a collection of particles of carbon, probably soot. ff, portions of yellow elastic tissue, probably from the areolar tissue of meat. /, portions of yellow fecal matter in various stages of disintegrative change. In some of these masses are seen minute particles of sand and other matters which have adhered to the surface, or have become mixed with the soft viscid matter. %, a small piece of mica. /, a portion of myelin from nerve-tissue which has been long macerated in the Thames water. m, collection of bacteria. m, bacteria in the shell of a diatom.

Fig. 2.— Also from Crossness Southern Outfall.—e, large spiral vessels from vege- table tissue (common cabbage). c**, two small spiral vessels still connected together as in their natural position in the tissues of the plant.

Fig. 3.—From a mud-bank off Erith.—d, crystals of fatty acids, the upper.d a collection of crystals of fatty acids. d**,a mass composed principally of oil- globules, with perhapsa little fecal matter. 4h, masses consisting of yellow fecal matter with a few oil-globules. 7, a glistening mass of very hard fatty matter. k, a minute fragment of mica. E

Ser. 2.—Vou. IV. B

2 Transactions of the Society.

interest to microscopical observers. To give an account of the diatoms only among the many constituents of this mud it would be necessary to recount the numerous memoirs published upon this important and highly interesting class of organisms from the time of Ehrenberg. I would venture to direct attention to the observa-

Puate II.

Fig. 4.—Bodies found in mud from Barking Outfall.—a, fragments of muscular fibre, partly dissolved by the action of the digestive fluids. The specimen onthe left still retains its transverse striz very distinctly. c, portion of spiral fibre of vegetable tissue, free from membrane. f, fine fibres of yellow elastic tissue, pro- bably from areolar tissue of meat taken as food. h, portion of yellow fecal matter undergoing disintegrative change.

In the following figures in plate IL. objects found in mud from a sewer close to Woolwich Pier are represented.—Fig. 5, fragments of deal wood. Fig. 6, a, mus- cular fibres exhibiting transverse strie very distinctly, with the exception of one, a, in the lower part of the figure to the right, which is a representation of a very small fragment partly dissolved. d, crystals, probably of fatty acids, set free by the decomposition of fatty matter. e, sporules of fungi. /f, fibres of yellow elastic tissue. g, a collection of granules, probably altered feecal matter. Fig. 7, a, fragments of muscular fibres in various states of disintegration. Fig. 8, c, spiral fibres from vegetable tissue; the lower figure represents a portion of a fibre set quite free from its enveloping membrane.

Puate IIT.

From an outfall of a sewer near to Trinity Ballast Ofice—Fig. 9, a, muscular fibres acted upon by the juices of the alimentary canal in much the same condi- tion as when they left the body with the fecal matter to pass into the sewer. Fig. 10, d, free crystals of fatty acids resulting from the decomposition of fatty matter. Fig. 11, c, spiral fibres from vegetable tissue. Fig. 12, a, muscular fibres partly acted upon and disintegrated. , epidermis from a leaf.

From a mud-bank off East Greenwich.—Fig. 13, a*, muscular fibre partly dis- solved but still showing a few transverse markings, d, crystals of fatty matter with some fecal matter. Fig. 14, d, fragments of white fibrous tissue, much decomposed and rendered granular by the action of the water and disintegrating agencies. jf, portion of thick yellow elastic tissue from the coat of a large artery. Fig. 15, 4, portions of stercoraceous matter with granules and oil-globules im- bedded in them.

Puate IY.

From a mudbank off Hast Greenwich.—Fig. 10, o, fragments of coal. 1, epithelial cells, probably from the mouth. Fig.11, very fine fibres of yellow elastic tissue.

From a mudbank at Chelsea,—Fig. 12, a, muscular fibre much disintegrated. h, masses of yellow fecal matter undergoing disintegration by the action of the water.

From an outfall of a sewer near to Trinity Ballast Office.—Fig. 13, c, fragments of spiral vessels from vegetable tissue. d, crystals of fatty acids set free by the decomposition of fatty matter. A collection of the same is represented in Fig. 14 at d. e, sporules of fungi. f, fibres of yellow elastic tissue, many exhibiting transverse markings produced by boiling old fibres.

From a mudbank at Chelsea.—Fig. 14, c, vegetable cells with spiral fibres. Fig. 15, s, a portion of cellular tissue from some vegetable, probably turnip. Fig. 16, p, fragment of white fibrous tissue much disintegrated and with nume- rous granules therein. a*, a portion of muscular fibre nearly transparent from maceration, but a few transverse markings still remain distinct. /, a small frag- ment of yellow elastic tissue showing vestiges of transverse markings. 0, frag- ment of coal. Fig. 17, a, portion of muscular fibre changed by maceration. 0, frag- ment of coal. Fig. 18, 0, fragments of coal. Fig. 19, portion of a very large mass of fecal matter containing many silicious and other fragments imbedded in it, and which adhere to the viscid matter of which it is in great part composed.

JOURN. R, MICR. SOC. SER. II. VOL. IV. PL. II.

STIG RETO

re

L.S. B. ad nat. del. 1883.

1/1000 of an inch '——! x 215 diameters.

JOURN. R. MICR. SOC. SER. II. VOL, IV

o Tbs Hill

hy } ws x af io} oe So pes 9 = aS Wa PS \ a ny Ws Ms Ma JT %

(C6, Ss

L. S. B. ad nat. del. 1883.

1/1ooo of an inch !—_! x 215 diameters.

JOURN. R. MICR. SOC. SER. Il. VOL. IV. PL. IV.

L. S. B.ad nat. del. 1883. 1/1000 of an inch |! x 215 diameters.

Constituents of Thames Mud. By Lionel S. Beale. 3

tions of this authority upon the diatoms of the Elbe, to those of Mr. T. F. Bergin on the deposits of the mud of the Liffey,* to those of Professor Bailey on the diatoms found in the Mississippi, to the paper of Mr. F. C. 8. Roper on the Diatomacee of the Thames,{ and lastly to the memoir of Dr. Bossey on ‘Thames Mud in relation to Sanitary Science. { Mr. Roper in 1854 and Dr. Bossey more recently have carefully studied the species of diatoms in different parts of the river, and have shown that the valves belonging to fresh-water species growing in the upper parts of the river may be carried down by the tide towards the mouth of the Thames, while the valves of those living in salt or in brackish water are to be traced as far up as the tide extends. These beautiful silicious skeletons so easily recognized and identified, being very light, are carried backwards and forwards by the tide, and are deposited on the mud-banks. ‘They may be regarded as evidence of the course taken by other light particles suspended in the water of the river, and afford one of many indications of the movements of the sewage. Thus we are able to show that at any rate the least dense of the constituents of sewage may be carried from the outfall at Barking up to the first lock in one direction and below Gravesend in the other.

It is impossible to exaggerate the importance of investigations concerning the course of the sewage in the river considered in con- nection with the changes effected in it by various agencies during its suspension and after its subsidence as mud. That our river is fouled by the presence of sewage is patent to every one, while most of us feel that its state is a disgrace to our city. The serious question which presents itself to Londoners, and mdeed concerns England, is whether this constant pollution of the river by the pouring into it daily of more than 100 millions of gallons, nearly 450,000 tons, of sewage can be continued without increasing risk to the health of the people, to say nothing of the disagreeable effects on the senses of sight and smell, and the very unpleasant considerations suggested by the contamination.

Some years ago there was unmistakable evidence of the occur- rence of a very nasty kind of decomposition proceeding in the Thames water. The air of all the streets bordering the river was polluted with offensive odours. During the last few years, however, we have not been so seriously annoyed. But it must be borne in mind that we have had a remarkable series of cool and wet summers, favourable to excessive dilution of the sewage and un- favourable to organic decomposition. What the state of things

* ¢Cooper and Busk’s Microscopic Journal,’ ii. (1842) p. 68.

t+ Trans. Micr. Soc. Lond., ii. (1854) p. 67.

t ‘Proceedings of the Holmesdale Natural History Club,’ December 12th, 79.

B 2

4 Transactions of the Society.

would be if we had a very dry hot summer succeeding to a spring with less than the usual rainfall it is not pleasant to contemplate, for | am afraid it is probable that the considerable reduction of the volume of water in proportion to the sewage would result in a concentration of the dissolved and suspended organic matters, which, gradually rismg in temperature from day to day to 70° or higher, would perhaps almost suddenly undergo a form of putre- factive change resulting in the setting free of large volumes of highly fetid gases, which would poison the air far and wide. Such a nuisance might persist for weeks, and only disappear when by the autumn rains the tidal water had become greatly diluted and its volume increased by fresh water pouring in from above. How far such a state of the river would be injurious to health it is not possible to say. I do not think anything of the kind upon so large a scale has ever happened, and any suggestion as to possible danger to health. not beg backed by actual facts, would only excite counter observations and assertions as to the excellent health enjoyed by those who spend much of their time in the sewers, and a review of facts, carefully selected by no impartial hand, with the object of convincing people that stinks were not unwholesome, and that possibly to the trained they might be actually enjoyable; that the presence of decomposing animal and vegetable matter sus- — pended in water was rather an advantage than otherwise; that countless multitudes of harmless organisms while ministering to their own enjoyment and advantage, exerted a beneficent influence by appropriating the products of disintegration just prior to decom- position ; and that upon the whole we ought to consider ourselves fortunate in possessing in our midst a large river reeking with filth, because in this way the noxious substances are slowly re- solved into simpler gaseous and soluble matters instead of the whole contributing to increase the already sufficiently ample mud- banks, which—and at a constantly accelerating rate—would add to the difficulties of navigation, and at length interfere with the passage of all but the smallest craft.

Method of Examination.

The large amount of gritty silicious particles, as well as their considerable size, renders the examination of small portions of mud just as it is obtained from the mud-bank very difficult. The layer placed on the glass slide and covered with thin glass will be too thick for examination by any but the lowest powers, and in con- sequence, some of the most minute but most important of the constituents of the mud will not be discerned. If a little of any specimen of mud be mixed with water, covered with thin glass, and then examined in the usual way, nothing but large sand-grains,

Constituents of Thames Mud. By Lionel S. Beale. 5

with here and there black particles of coal or carbon, will be seen. By mixing a small portion of mud with a considerable quautity of water, stirrmg it up, and then pouring off the upper part of the fluid after allowing a few seconds for the subsidence of the heaviest and coarsest particles, a deposit may be obtained in a state fit for examination under tolerably high magnifying powers, and if the process be repeated again and again, the mud may be separated into several portions differing from one another in density and in the coarseness of the gritty particles. But this plan is found not altogether satisfactory, for many of the organic substances in the mud are only imperfectly seen, while it will be impossible for the observer to form any idea of the relative proportions of the various constituents of the mud thus divided into separate portions differing from one another as regards the size and lightness of the component particles.

After having tried many different methods of investigation, I found that admixture with an equal quantity of glycerine afforded the best results. In this process the specimen can be kept for a length of time without undergoing change and be submitted to examination at intervals. The refracting property of the glycerine enables the observer to make out details of structure which could not be seen in specimens immersed in water, while in each specimen almost all the constituents of the mud are rendered clearer and more distinct.

Another important advantage is gained by this method of examination, inasmuch as the observer is able to form a notion of the relative amount of the several substances in each specimen examined, and also the relative amount of each in any given specimen. By this plan every constituent of the mud may be seen in one preparation, and specimens prepared in this manner have the additional advantage of preserving their characters for many years without change.

Ifa portion of the mud is simply mixed with water and then stirred up, the heavier particles allowed to settle while the lighter ones are poured off into another vessel and then allowed to subside, a very wrong idea may be formed of the number of the lighter substances present, because nearly the whole of these in the quantity of mud operated upon may be separated, and the microscopical specimen would in that case appear as if it consisted almost entirely of this one class of constituent particles.

This paper is based upon the results obtained by the micro- scopical examination of twenty-five specimens of mud from various banks between Gravesend and Chelsea taken under the direction of Dr. Collingridge, the Port of London Sanitary Officer, in the course of an inquiry undertaken at the request of the City of London for the purpose of obtaining evidence to bring before the Royal

6 Transactions of the Society.

Commission appointed to consider the question of Thames Pollution. I have received permission to communicate the results to the Society, and to publish them.

The observations made by me relate chiefly to the organized constituents of the sewage which can be demonstrated in the mud of the Thames by microscopical examination. Many of the particles found in the mud have been identified as substances which had entered into the formation of human excrements. I have en- deavoured to ascertain what changes some of the most important of the feecal constituents undergo in their passage from the houses along the drains into the river until their disintegration is at last completed or they have been deposited and form part of the mud banks of the Thames.

The broad and important fact which is, in my judgment, fully established by the investigation is this—that several constituents of human feces are present in all the specimens of mud submitted to examination. The amount of these differs considerably, though no adequate means have been discovered of making an accurate estimate of the quantity of any one of them, or of instituting more than a very rough comparison between the muds obtained from different banks.

It must be borne in mind that the river mud is continually undergoing change in its character, the surface of the bank being often washed away, and old matters being mixed up with the elements of recent sewage; these being deposited together in other and perhaps distant banks, as determined by the varying quantity of water, the rate of its flow, and a number of other circumstances. Thus the mud of any given bank will vary considerably in its characters at different periods of the year, and it is quite supposable that a bank, which at one time would be found to consist of nearly pure sand, at another might seem to be almost entirely composed, at least on its surface, of the blackest and foulest organic matter undergoing rapid putrefactive changes.

It is well known that the quantity of organic matter in the mud is small. If a certain portion of the mud be dried and then exposed to a red heat for a time, the loss in bulk owing to the total destruction of the organic matter and the dissipation of all volatile substances is very slight. On the other hand it is to be remarked that neither the disagreeableness nor the danger to health of organic matter in a state of decomposition is dependent upon or varies according to the amount present. From a quantity of certain forms of organic matter so small that it would fail to turn the most delicate balance, as for example a fraction from the specimen of sewage taken from an outfall near Trinity Ballast Office, an odour of a most detestable character might emanate and be diffused over a considerable area. But it must be borne in mind that as regards

Constituents of Thames Mud. By Lionel S. Beale. 7

animal and organic poisons dangerous to life, it is an admitted fact that a quantity easily carried by a very small fly might be suf- ficient to infect a considerable number of persons; and therefore the fact of the small proportion of organic matter in the Thames mud and in suspension in Thames water cannot reasonably be adduced as an argument in favour of its innocuousness or of its unimportance. But the relative proportion of the organic matter as well as its deleteriousness no doubt varies greatly at different times. I believe all the specimens of mud examined by me have been taken when the river was in flood, or soon afterwards, and at a time of the year when putrefactive decomposition is slowest. From the state of things under these favourable conditions it is hardly possible to determine how very unsatisfactory might be the state of the mud and of the river in hot dry weather. Year by year the actual quantity of sewage must increase, while the amount of water remains the same. In recent years the amount of water in the river and the rainfall have been above the average. At this time (November—December 1882) the degree of dilution is no doubt ample in proportion to the amount of sewage flowing into the river, but even under these favourable conditions disintegration is a very slow process. As the sewage poured into the Thames remains diffused in the water for a substantial time, at some periods of the year the putrefying sewage will be in too large a quantity in proportion to the water in which it is suspended to be properly disintegrated and oxidized, and in too concentrated a form to be appropriated by living animals.

Constituents of Food found in Thames Mud.

Of the constituents of human food altered by the process of digestion and by subsequent maceration and disintegration, and by oxidation, not a few are to be found in the mud of the Thames, deposited from the water as it flows up and down the river. It might be supposed that in consequence of the long distance traversed in the sewers and the length of time during which they are suspended in the tidal water, few of the matters in question would be obtained from the mud-banks in a state in which they could be recognized with any certainty by microscopical ex- amination. But in fact a number of bodies with well-marked and unmistakable characters have been found. Among these may be mentioned starch-granules, fragments of vegetable tissue, large spiral fibres of various plants, but particularly of common cabbage, all of which have already passed through the alimentary canal. Tea-leaves, fragments of cooked muscular tissue and yellow elastic tissue in a state in which one often finds them in fecal matter, cotton fibres, probably from paper, fatty matter, and crystals of

8 Transactions of the Society.

fatty acids. Even blood-corpuscles of man or of one of the higher: animals have been detected in the mud, having withstood all the destructive agencies to which they have been exposed during probably many months. Fragments of paper and rags and many other things are also present, but it is to those substances which are found in the excrements that my attention has mainly been directed.

Fragments of Vegetable Tissue in Thames Mud.

In every specimen of mud examined many fragments of vege- table tissue have been found, but considerable variation exists in different banks, both as regards the character as well as the quantity of vegetable tissue present. Some of the fragments of vegetable tissue found in the mud of the Thames are doubtless derived from plants which grow on the banks, and which in various ways and from many sources find their way into the river; but that the great majority of such fragments are derived from the sewage and have already passed through the alimentary canal is proved by the yellow colour they have taken from the fecal matter. If healthy faeces be examined after a person has eaten a quantity of cabbage or other vegetable, many fragments of vegetable tissue stained of a deep yellow colour will be found, and the appearance of these is very similar to that of many of the fragments seen in my specimens of mud taken from the mud-banks. It is remarkable that, in its passage through the intestines, colourless greenish or pale-brown vegetable tissue becomes infiltrated with yellow colouring matter, and is thus sometimes deeply stained of a bright yellow, and this stain is very persistent.

Spiral Vessels.

In nearly all the specimens of mud I have examined I have found fragments of spiral vessels, many of which are very large and of great length. The majority are undoubtedly derived from the common cabbage, while some are clearly connected with portions of tea-leaves, of which numerous fragments have been discovered in most of the specimens submitted to examination.

If a portion of the stem of a well-boiled cabbage-leaf be ex- amined numerous large spiral vessels exactly like those I have found in the mud will be discovered. In most of them the mem- brane of the vessel is destroyed or so softened by boiling that the spiral fibre protrudes, and in many cases is almost entirely un- coiled. On comparing these spiral fibres with many of those in the mud the similarity will be at once recognized. ‘The resisting power of the spiral fibre is shown by the fact of its retaining its remarkable characters not only after prolonged boiling, but after it

Constituents of Thames Mud. By Lionel S. Beale. 9

has been exposed to the action of the digestive fluids poured into different parts of the alimentary canal, after it has passed through the sewers, and after it has been carried backwards and forwards by the tide, and exposed perhaps for months to various disintegrating actions constantly taking place on the mud-banks of the ‘lhames. Spiral vessels, plate I. figs. 1 c*, 2; plate I. figs. 4¢, 8; plate III. fig. 11; plate IV. figs. 13 ¢, 14.

Starch-granules.

In several specimens of mud I have found starch-grains, and have been able to distinguish wheat starch, potato starch, and rice starch by the shape and size of the grains and by the action of iodine. Many specimens of wheat starch are much altered, and look as if partly digested. These I think have probably been derived from bread, and have passed through the alimentary canal. Starch has also been found in many cells of vegetable tissue, the exact nature of which I have not been able to determine.

Muscular Fibres.

In almost every specimen of Thames mud examined by me muscular fibres or bodies which were recognized as the result of changes in muscular fibres were found. The fragments varied much in number as well as in size in different specimens of mud, but were most numerous and the anatomical characters of the fibres most distinct in the sewage taken direct from the mouth of the sewer and in the muds near the outfall. Many of the fibres were firm and hard, and had all the character of muscular fibres which had escaped the action of the digestive fluids in their passage along the alimentary canal, and which are very frequently, though not constantly, found in fecal matter. The fibres in question are for the most part derived from beef. It is most interesting to study the changes which may be observed in the character of the fibre as it passes from the condition in which it is found in recent feces, with its well-known and remarkably well-marked anatomical cha- racters, to its final disintegration in the river and on the mud- banks of the Thames. Some of the most remarkable alterations in the microscopical characters of the fibres are illustrated in my preparations and represented in my drawings. In fresh fecal matter some of the fibres exhibit the ordinary character of coagu- lated and well-cooked muscle tissue which has escaped the action of the gastric juice and intestinal fluids. The transverse markings are very distinct and are sharply defined, the fibres are firm and hard, and bear considerable pressure without being damaged.

In other specimens the action of the digestive fluids upon the fibres is very manifest, all appearance of transverse strie being lost

10 Transactions of the Society.

and the substance of the fibre appearing clear and jelly-like and of a faint yellow colour. Some of these transparent yellow masses are evidently undergoing disintegration and are pervaded by minute granules. Actual bacteria, which are active agents in destruction, are also often present in great numbers. In the muds of different banks it is not difficult to find examples of muscular fibre which illustrate every stage of disintegration up to the final conversion of the substance of the fibre into adipocere. Some of the fibres are probably softened at the time they leave the body. These are soon further disintegrated, silicious and other particles adhering to them ; and the compound masses thus formed are gradually and at length completely disintegrated. Fragments of muscular fibres in various stages of disintegration are represented in plate I. fig. 1 a; plate II. figs. 4.a,6a, 7; plate ILI. figs. 9, 124,13 a*; plate LV. figs. 12a, 16 a*, 17 a.

Yellow Elastic Tissue.

Many fragments of different kinds of yellow elastic tissue are found in the mud-banks of the Thames. This substance long resists decomposition, and it is probable that many months or even years may elapse before some of the firmest particles are completely disintegrated. The characters of elastic tissue vary according to the texture from which it has been derived. The fibres differ so much in structural peculiarities that it is often possible by microscopical examination to say whence they had been derived. I have identified fibres from the ligament of the neck, probably of the sheep, yellow elastic tissue arranged as a network from the coats of a large artery from the same animal, fibres from the lung and from the areolar tissue of the body. Not only so but some of the yellow elastic fibres in my specimens exhibit those peculiar transverse markings which show the fibres | to be old and also indicate that they have been well cooked. (Plate IV. figs. 13 f, 16 f.) Yellow elastic tissue, it seems, passes through the alimentary canal without being acted upon by the digestive fluids and is therefore always found in the faeces when it has been taken with the food. Portions of yellow elastic tissue are represented in plate I. fig. 1 f; plate Il. figs. 4 f, 6 /; plate ILI. fig. 14 f; plate 1V. figs. 11, 13 f, 16 f.

Yellow Fecal Masses.

Amoug the most striking constituents of Thames mud are yellow granular masses varying much in size. The smallest of them are mere granules or small collections of very minute eranules, and less than 1/100,000 of an inch in diameter, the largest as much as the 1/50 of an inch in diameter or even more.

Constituents of Thames Mud. By Lionel 8. Beale. 11

These yellow masses have been described by Dr. Tidy in a Report to the Conservators of the river Thames, written in the year 1881.

The colour of these masses varies from a dull or dirty brown to a bright yellow colour. Some are smooth and homogeneous in parts, others rough and irregular containing particles of man different kinds, some of which have been associated with the yellow matter from the first, while others have been added while the matter was in the sewer or in the river.

As portions of fecal matter are driven backwards and forwards by the tide, besides undergoing disintegration as has been already described, the opposite process of integration is also going on. The collection and aggregation of particles of many different kinds to form oval masses is always taking place. ‘These composite masses consist of numerous minute particles of sand, many fragments of carbon, small portions of diatoms, oil-globules, fatty acids, and many other things apparently cemented together by the yellow viscid substance which forms an important constituent of feces. Many of these compound masses are as much as the 1/50 of an inch in diameter.

Incessant changes, mechanical as well as chemical, are con- tinually proceeding in the organic matter of sewage, but, as has been shown, these changes are not purely destructive and dis- integrative.

It may be said that all the animal and vegetable tissue and other constituents of feeces with actual faecal matter present, do no harm because they are constantly being disintegrated, while many low vegetable and animal organisms live at their expense and grow and multiply exceedingly and consume them. It may be said that by these means and by oxidizing and other disintegrating processes, all the organic matters present in sewage are gradually resolved into substances which are not in the least degree deleterious either to fishes and other organisms living in the water of the Thames or to the inhabitants of the houses near the river. Such statements may be made and supported by facts. Arguments telling in the same direction may be freely admitted without the strong objections to the presence of these things ima tidal river being in the slightest degree diminished, much less removed. Yellow fecal masses of various sizes are seen in plate I. figs 1h, 3hh; plate Il. fic. 4h; plate III. fig. 154; plate IV. figs. 12h, 19.

Fatty Matter, Oil-globules and Fatty Acids.

y

The fatty matter varied much in different specimens of mud. It existed in the form of amorphous granules, in globules, and as crystalline particles probably consisting of fatty acids set free in consequence of decomposition. Many compound masses were made

12 Transactions of the Society.

up of granules and globules of oily matter, minute granules of silicious and other inorganic substances, fragments of vegetable tissue, starch-globules, all connected together by a viscid cementing substance of a yellowish colour which was probably the fecal matter already referred to.

Such complex masses no doubt slowly undergo disintegration. By mere attrition the organic matter on the surface would be gradually removed and would form at length a very fine mud which would slowly settle, while probably a smaller portion would be subjected to chemical change and be ultimately dissolved. Fatty matter and crystals of fatty acids are seen in plate I. figs. 1 d, 3; plate Il. fig. 6 d; plate III. figs. 10, 18 d.

Particles of Soot and Coal.

There is no difficulty in discovering minute pieces of coal in the mud, and in some instances I have found indications of vegetable structure in the sections and delicate fragments of coal which have accidentally resulted from the action of the water and the rubbing together of particles as they were driven backwards and forwards by the current.

Much of the soft black matter present in the mud is no doubt soot. Even particles of silica are sometimes found soot-stained. Perhaps such black sand is derived from the smoke-impregnated sranite débris of the macadamized roads. Black particles of coal and other forms of carbon are represented in plate I. fig. 1 d*; plate IV. figs. 10 0, 16 0, 17 0, 18.

Diatoms.

More than 100 different species of diatoms are found in the Thames, some being peculiar to fresh water, some to salt water, while the natural habitat of some specimens seems to be water which is always brackish.

The silicious skeletons of the valves of diatoms that have died, and multitudes of fragments of valves in every degree of disintegra- tion are found in Thames mud. After the removal of the particles of sand a considerable portion of the inorganic matter of the mud that remains probably consists of the débris of the valves or shells of these organisms.

As long ago as 1853 Mr. F. C. 8. Roper published some interesting observations on the ‘ Diatomaceze of the Thames’ * and gave a list of 104 species from the mud of the Isle of Dogs alone. Of these 30 are decidedly marine, 29 belong to brackish

* Trans. Micr. Soc. Lond., ii. (1854) p. 67.

Constituents of Thames Mud. By Lionel S. Beale. 138

water, and the remaining 45 are fresh-water species. As would be supposed, some of the marine species are carried up the river, and the fresh-water species downwards towards the sea. Mr. Roper found marine species at Hammersmith, but very few fresh-water species were met with as low as Gravesend. “At Gravesend, out of 47 specimens 8 only are decidedly peculiar to fresh water, whilst at Hammersmith we find there are 29 fresh- water species out of a total of 43, showing however that the influence of the flood tide, even at that distance from the sea, gives a decided character to the diatomaceze deposited by the water.”

Of the diatoms met with in Thames mud, some are found in a living state, but the majority are not only dead but they do not belong to the particular locality where their remains have been dis- covered. ‘The silicious shells or valves of these organisms are very light and are often transported long distances. Suspended in the moving water, many pass up and down the river and probably form a part now of this bank, now of that. By this continual movement, and by rubbing against sharp particles of sand and by being buried in it, and then again disturbed, such delicate structures necessarily become disintegrated, and are at last broken into those very minute silicious fragments which exist in great numbers in the mud of all the mud-banks examined.

Mud-banks, especially on the surface, are in a state of constant change. Formation and destructicn, accretion and disintegration are continual, and, when the facts are considered, one cannot feel surprised that organisms which are formed high up or low down the river, or at least parts of them, should eventually be discovered in a resting place at a long distance from the seat of their deve- lopment. Bodies formed high up the stream may be deposited at its mouth, and those which inhabit the sea or brackish water may be carried far up into the region traversed by and exposed to the action of fresh water only. In fact, the ascent and descent of light particles is clearly shown by the distribution of the diatoms on the banks in different parts of the river, and this fact alone would render it certain that many of the constituents of sewage would in like manner be carried up and down by the tide, and that some would be found a long way from the point where they first entered the Thames.

Bacteria.

are found in immense numbers in all the muds I have examined, and exist in multitudes in Thames water, and in connection with all the particles of organic matter held in suspension in the water, or which have subsided to the bottom, or have fallen on the leaves of plants or other objects which have prevented their further sub- sidence. Bacteria are so very minute that they may easily be

14 Transactions of the Society.

passed over unless a very thin stratum of the fluid which holds them in suspension be examined. ‘Though so small, they are probably bodies of the very highest importance in the disintegra- tion of sewage compounds. The germs of these organisms are excessively minute, many being less than the 1/100,000 of an in. — in diameter, whilst the smallest are probably not to be seen when amplified by the highest magnifying powers at our disposal. So very small are they that they must grow for some time before they are of a size sufficient to be rendered visible by an objective which magnifies upwards of 5000 diameters. Bacteria germs exist everywhere in countless multitudes, not only in air and in water — and on the surface of every kind of matter, but in the interior of, bodies living as well as non-living wherever fissures exist, and chinks are seldom absent through which germs so minute can pass. Not only are bacteria always to be found upon every part of the surface of all living beings, but they exist within the blood, and in the very substance of the tissues however distant from the external surface of the body, and however far from any direct communica- tion with the outside air. In all animals and in all plants, at all temperatures consistent with life—in every part of the world— bacteria are living at this moment, and they have lived, and pro- bably in the same way as they live now, in every period of the world’s history from the earliest dawn of life. Soon after the death, and in many instances long before the death of a man or an animal has taken place, the bacteria germs, which have been dormant in the tissues and fluids, begin to grow and multiply enormously, so that in a very short time every part is freely per- vaded with countless hosts which soon stop all ordinary action and efface all characteristic structure. ‘Then begins that long series of changes which ends at last in the formation of products of com- paratively simple character and very stable nature.

Extremely minute division of the organic matter of sewage and its equable diffusion through a large volume of water in constant motion are favourable to the conversion by bacteria, of noxious matter into chemical compounds, which are inodorous and harmless, and which undergo but slight change whether moist or dry, and which are usually at last disposed of by becoming the food of plants. In the case of sewage this desirable change into innocuous compounds is rendered very slow in consequence of the matter not beg spread out in a sufficiently thin layer to be quickly appropriated by the bacteria.

The rate of growth and multiplication of bacteria varies greatly at different periods of the year. These organisms are not destroyed by ordinary cold; nay, there is evidence that bacteria multiply after having been exposed even to intense cold, but of course very slowly as compared with their rate of increase under

Constituents of Thames Mud. Ry Lionel S. Beale. 15

favourable conditions. The changes effected by them on the products resulting from the death of man, the higher animals, and plants, are, and probably have ever been, the same in their essential nature at all times, but a longer time is required for the completion of the changes in cold than in warm weather.

Although chemical change, irrespective of the action of living forms, and especially the action of oxygen, undoubtedly plays an important part in the disintegration and reduction to simpler and more stable compounds of some of the constituents of sewage, particularly the excrementitious matters of the human body, by far the most extensive changes, and those effected on the largest scale, are brought about by these minute organisms. Bacteria are among the lowest and simplest living forms in nature, and as I have men- tioned are universally present, or at least are to be found wherever moisture-laden air exists. Some forms of these bodies do not even require oxygen for their subsistence. They can live in nitrogen, carbonic acid, and probably in gases of the most poisonous and deleterious character for a length of time, though they do not grow and multiply quickly until conditions favourable to them are established.

In the present state of knowledge it is not possible to explain precisely how these organisms act upon the offensive sewage matter, but it is probable that as they grow and multiply they actually feed upon and consume the noxious material. After living its life the bacterium dies, and the products arising from its decay and disintegration are harmless indeed as compared with the substances upon which it has fed, and which for the most part it is our great anxiety to be rid of. The matters resulting from the disintegration of bacteria in turn become the food of plants. If not taken up by vegetation these compounds would remain passive as a soft brown granular material which is stable, and undergoes scarcely any change whether it remains constantly moist, as in mud, or sometimes dry and sometimes wet as the humus of earth. Few organic substances undergo so little change from century to century, nay, from age to age, as for instance those products of plant decay which constitute the principal con- stituents of various kinds of peat. The same may be said of the last products of the decay of animal matter. For after the offensive gases which characterize the ordinary putrefactive change of animal matter have been evolved, and the putrefactive process has run its course, slow evaporation takes place, and, after hundreds and thousands of generations of bacteria have passed through the several phases of existence and have died, there results a brown substance which preserves its characters for centuries, and probably undergoes no further change at ordinary temperatures.

In the disintegration of the substances resulting from the death

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of the higher plants and animals there is no doubt that many forms of life take part, but when at length these have lived and disappeared, bacteria continue the processes, and it is, as I have remarked, by their action that the organic matter is caused to assume its final form in which it may remain for any period inno- cuous to all forms of life. The brown matter which remains after decay has run its course, consists mainly of the lifeless remains of bacteria.

Disintegration by bacteria begins in the living organism itself. There is no part of the alimentary canal or of any of the ducts, tubes, or cavities opening into it, in which multitudes of these organisms, growing and multiplying in countless millions, cannot and at all times be found. It has undoubtedly been assumed by many observers that whenever bacteria are discovered in the cavities, tissues, and organs of living animals they have been introduced from without. But the assumption and the conclusions based upon it are erroneous, as any one who will make the investi- gation with due care may easily convince himself. In the cavity of the mouth they are always and in all states of health in all animals growing and multiplying excessively. Even in the interior of the cells of plants, cabbages, lettuces, watercresses, &c., as well as in the interstices of the inmost tissues of the higher animals and of man, they or their germs exist, and when the con- ditions become favourable, they grow and multiply in enormous numbers. Many of the bacteria present in the water and in the mud of the river have no doubt been derived from bacteria which existed in the excrementitious matter before it left the organism in which it was formed. These probably go on growing and multiplying in the organic matter while in the Thames, and are not the least important agents in its disintegration and ultimate resolution into harmless compounds.

Practical Considerations.

Tn conclusion, I shall venture to make a few observations con- cerning the practical inferences which are suggested by the present inquiry. Although no doubt a physician is likely to take a rather limited, fragmentary, and possibly not impartial view of many of the most important matters which bear upon the great question of the proper disposal of sewage, while to effectually grapple with the difficulties, engineering knowledge and skill are required which none but the trained engineer can possess, it neverthe- less seems permissible, and since no harm can thereby result, I think it may be desirable that those engaged in other departments of the inquiry should briefly give expression to their views. The subject is one which cannot receive too much consideration before the mode

Constituents of Thames Mud. By Lionel 8. Beale. 17

in which it is to be practically dealt with is decided. I have often wondered whether, besides the Thames, there is another river in the world, on the mud-banks of which could be found in equal quantity, particles of feecal matter, fragments of muscular fibre in every stage of disintegration, fibres of yellow elastic tissue, spiral fibres from vegetables, and many other constituents of food which have passed through the human intestinal canal, with other organic matters in a state of decomposition, discharged as sewage, to undergo disin- tegration in the river, and there become resolved at last into harmless matter.

It is said with truth that London is the healthiest city in the world, but the possibility that our river may any summer seriously damage our reputation must not be lost sight of: year by year the proportion of sewage to the water increases, and the particular point at which the sewage contamination becomes dangerous to health is unknown, for there is no experience to guide us, while so many circumstances contribute to the maintenance of its present harmless condition on the one hand, and such comparatively slight departures from the ordinary conditions might cause disaster on the other, that the problem is one of the most complex and difficult that could be presented for solution ; while it is doubtful whether the precise changes that would endanger the public health could be discovered by experiment and determined beforehand. In fact there is much uncertainty, though little ground for satisfaction.

Granting for a moment the correctness of all that has been said in favour of the state of the river at this time, granting that at present the sewage is carried away, there remains the important question whether without very considerable changes the removal of the sewage in the course of a few years will be as efficiently carried out as it is now. ‘The amount of sewage is constantly in- creasing, the amount of water by which it is diluted remains the same. Must not the time come when the proportion of sewage to the water becomes so large that its disintegration and harmless decomposition within the proper time will be impossible ?

As long as the sewage is passed into and immediately mixed with a very large volume of water, our drainage system is no doubt very effective, possibly as near perfection as can be expected in a case where the removal of the sewage of a population of four millions has to be provided for. During the greater part of the year the sewage 1s no doubt sufficiently diluted as it passes along the sewers, while these are well scoured by the flow through them; but when little rain-water is added to the water supplied by the com- panies, what will be the state of the sewage? So far, therefore, from the surface rain-water being diverted and prevented from passing into the sewers, every arrangement ought to be made to facilitate its flow into and exit from them.

Ser. 2.—Vot. IV. ce)

18 Transactions of the Society.

The smell of the river and of the mud some years ago, when the amount of sewage poured into the Thames probably did not amount to more than half the quantity now traversing the sewers, perhaps affords some idea of what might happen if the conditions favourable to the development of smell were repeated and aug- mented in intensity, as will probably obtain when a very dry hot summer follows a winter and spring in which the rainfall shall have been considerably less than the average, unless in the mean- time some more effectual and quicker means of disposal of the colossal amount of the sewage should be discovered and carried into practice. As London increases, therefore, every effort should be made to keep up and increase the amount of water mixed with the sewage at its source so that it may attain the greatest degree of dilution that is practicable during its transit along the sewers.

Any one who has seen the vast volumes of water in the upper Thames during the time of flood will be convinced that there is water and more than enough to flush the sewers of a city even consider- ably larger than London. If only a small portion of this vast quantity of wasted water could be husbanded till the time approaches when the amount at our disposal for diluting the sewage could be thus supplemented, the efficiency of the present system would doubtless be greatly increased. Unless the plan for dealing with the sewage can be completely changed, it will be necessary, as time goes on, to further enlarge the present sewers, to divert into them sewage which even now finds its way into some of the tribu- taries of the Thames, and to carry further and further towards the sea the mains which receive the sewage and drainage collected from that increasing area included in Greater London. That such operations would entail vast and lasting expenditure is obvious, but basing our conclusion on the practical results achieved during the past thirty years and more, is it not highly probable that all that can be desired would be gained? On the other hand, it may be asked which of the several other suggested schemes of sewage disposal has been found to succeed on a sufficiently large scale, and for a sufficient length of time, to justify its adoption in place of the main drainage system now in operation ?

_By mixing sewage with large quantities of water the gradual disintegration and oxidation of many of its constituents and the slow conversion of all its deleterious principles into substances which are at any vate harmless, is insured. ‘The changes are in part mechanical and chemical, and partly due to living organisms, which play no unimportant part in the ultimate reduction of noxious organic matters to harmless compounds. The rapidity and completeness of the purification of the contaminated water in great measure depend upon the degree of dilution. If the sewage is con- centrated, the decomposition which ensues is of a different kind and

Constituents of Thames Mud. By Lionel S. Beale. 19

results in the formation of compounds of a most offensive and dele- terious kind, which are afterwards only very slowly converted into harmless substances. If the sewage passed into the sea in such a manner that it became quickly diluted, it is probable that for miles round, at a considerable distance from the outlet, organisms of many kinds would grow and multiply in vast numbers. Many of these would become the food of fishes, which in their turn would be taken and help to support the population which had already supplied their sustenance.

That objections may be advanced to some of the details of the drainage system now in operation is no doubt true, but the experi- ence of many years has conclusively proved that it is workable, and the results of its working may, I suppose, be considered fairly satis- factory. The practical working of the main drainage system seems to have shown that if only sufficient quantity of water for dilution can be provided, and a good outlet to the sea obtained, the sewage of a city, however large, might be quickly and thoroughly disposed of, and the sanitary condition of houses, however numerous, at least as far as sewage is concerned, assured, while the alterations rendered necessary by the gradual increase of population, could be carried out from time to time as required, by the enlargement of the sewers and their extension towards and into the sea.

20 Transactions of the Socrety.

IJ.—On the Mode of Vision with Objectives of Wide Aperture.* By Prof. E. Aspz, Hon. F.R.MS. (Read 12th April, 1882.)

Tue idea of “all-round vision” as a peculiar capacity of wide- angled lenses has been put forward with opposite aims. The object of one side has been to indicate an advantage of wide aperture- angles in the vision of solid objects, depending on the angles qua angles and the admission of rays from all sides of the object at the same time. The other opinion claims that this must be a disadvantage, constituting an unnatural mode of vision, causing particles to look spherical (when sufficiently minute) even if in reality cubes, and giving rise to a confusion of dissimilar images.

The tacit supposition of both views is, that the optical conditions of microscopical observation are essentially the same, even with the minutest objects, as those of naked-eye vision—that a solid object is depicted through the Microscope in the same perspective, in which it would appear to the eye in ordinary vision, if it were looked at an the direction of the delineating pencils.

They assume, for example, that a minute die abcd (fig. 1) if depicted by means of oblique pencils r (such as are admitted through the marginal zone of a wide-angled objective) will appear in the microscopic image with the perspective in which it would be seen by an eye in the direction of r. It would thus appear as the projection of the die on a plane P perpendicular to the direction 1, or, which is the same thing, as it it were placed in an inclined position on the stage under axial illumination (fig. 2).

Fig. 2.

In fact it is supposed that obliquity of the delineating pencils to the axis of the Microscope is equivalent to and produces the same effect, in regard to the manner of projection of the image, as an oblique position of the object under perpendicular (axial)

* The paper (received 3rd March 1882) is written by Prof. Abbe in English.

Its publication has been delayed pending the completion of Prof. Abbe’s paper in the last volume.

On the Mode of Vision with Wide Apertures. By Prof. Abbe. 21

incidence of the pencils, and on the basis of this view the natural conclusion of course is that as a wide aperture admits pencils of very different obliquities at the same time, the resulting image must embrace as many different perspectives of the solid object, depicting them to the observer’s eye at the same time, just as if many narrow- angled objectives (or eyes) A, K, Z, &c. (fig. 3) were arranged around the object aud their images united.

According to the point of view adopted, or to the private taste of the writer, this, as I have said, is considered either as an advantage of wide- Fie. 3. angle vision, or as a drawback. eS

The fact is, however, that neither the one nor the other of these views is correct, \s) because no delineation of the objects takes place in the manner supposed. This is Ka shown by the following consideration, which also shows at the same time the error of the view that the resultant image of an objective of wide aperture is composed of dissimilar images projected by rays of different inclinations, for this is based on the same hypothesis essentially as the others just referred to.

First consider the case of a plane object. The course of the rays through a wide-angled objective is shown in fig. 4, the object being at A B. If we suppose the objective to be well corrected (or aplanatic) all rays emanating from the axial point’A (i.e. the whole pencil a) will be collected at one point A*, and the same igs true not only for an axial point, but for an eccentric point B also (up to a certain moderate distance from the axis at least).t Consequently the whole pencil 6 from the point B will be collected also to one distinct point B* of the image.

Now it is an evident inference that the plane A B must be delineated exactly in the same manner (as the same plane A* B* of the image) whether it is delineated by the two awial pencils aa and Ba, or by any two oblique pencils am and 8 m, whatever be their inclination to the plane of the object. For if all rays from B are collected to the same point B*, the two partial pencils 6 a and 8 m, which are parts of the whole pencil 8, cannot be collected to different points.

+ This idea of a well-corrected system has been considered formerly as quite unconditional. It has been supposed that whenever the rays from the axial point A are collected to a sharp focus, the rays from excentrical points B would always be collected to sharp foci by themselves. I showed in 1873 that the latter is not a necessary consequence of the former, and that a particular condition must be fulfilled in order to have the same collection of rays from excentrical points as is obtained from an axial one when the spherical aberration is corrected. This condition is the law of aplanatic convergence—proportionality of the sines of the angles at the foci A and A*.

22 Transactions of the Society.

Thus it is certain from the simple notion of an aplanatic system that pencils of different obliquities must yield zdentical images of every plane object or of a single layer of a solid object. However large an aperture may be, the resultant image of the object cannot therefore be composed of dissimilar images, and the wide aperture cannot be the cause of confusion, &e.

We see also at the same time that the delineation of an object through the Microscope does not ex- hibit differences of perspective according to the obliquity of the delineating pencils to

a the entire pencil starting from the axial point A of an object, and collected to the axial point A* of the image.

B the entire pencil starting from an excentrical point B collected to the excentrical point B* of the image.

aa and am an axial and a marginal elementary pencil from A which are contained within the pencil a.

Ba and Bm corresponding axial and marginal elementary pencils of the whole pencil B.

The two axial pencils aa and Ba pass through the central part, a, of the clear opening: the marginal pencils a mand 6 m touch the margin of the opening at m.

The limiting diaphragm of the clear opening is assumed to be at the plane of the posterior principal focus (as is always the case approximately with high powers) in order to obtain the corresponding rays of the two pencils a and B parallel in front of the system, or the same obliquity of a m and B m.

the plane of the object, as is the assumption of the all-round vision theory. The image of any plane surface AB (e.g. the upper surface of the minute die) is always the same whether the rays are admitted to the Microscope in per- pendicular or in any oblique direction. If that theory was right, the image of AB, by the oblique pencils am and @m ought to be shorter (according to the perspective shortening of the lines in oblique projection) than the image by the axial pencils aa and Pa, as we should of course have a shorter image of AB if we observed it through a low-power Microscope with inclined axis.

This absence of perspective shortening of the lines according to the obliquity of the rays exhibits therefore an essential geo- metrical difference of microscopic vision, which renders it uncom- parable to macroscopic observation.

Secondly, consider the delineation of a solid object such as a minute die.

On the Mode of Vision with Wide Apertures.

By Prof. Abbe. 23

This is of course perfectly defined by determining the delinea- tion of the upper plane surface A B, and of the lower A, B, (fig. 5). The result of the previous consideration must apply to both plane

surfaces successively, pro- vided their distance along the axis is sufficiently small. For in this case, an objective which is aplanatic for the conju- gate points A and B will still be aplanatic for the neighbouring pair of con- jugate points A, and B,. Consequently the whole pencils a and 6 from the surface A B will yield a distinct image A* B* at acertain plane, and at the same time the whole pencils a,, and £,, from the other surface A, B,, will also project: a. distinct image A,* B,* at another (lower) plane. Suppose (1) that the image is delineated by means of narrow axial pencils aa and Ba, and the ocular focused to the exact level of the lower layer A,* B,*. The points A* and B* of the upper layer will in this case ap- pear as small dissipation circles projected upon the distinctly seen points A,* and B,* of the lower layer, the centres of these circles ’ coinciding with the latter. Suppose now (2) the image to be delineated by

Fig. 5.

* *

Ae Be) air image of the object ( ie B as projected by the objective to the field of the ocular.

The diagram shows the manner in which the two successive layers A B and A, B, of the ob- ject are delineated by means of the whole pencils (full aperture pencils) a, 8 and a, 8,, or by - means of the elementary pencils a a, Ba, and a,a, B,a, or am, Bm and am, Bym, and indicates the manner in which the image of the upper layer is seen projected upon the image of the lower layer. The thick lines indicate the dia- meters of the circles of indistinctness which represent the points A* and B* under various circumstances at the plane of the lower layer (in one case broad and in the other small) on the assumption that this lower layer is exactly focused and seen in perfect distinctness.

the whole aperture, i.e. by the wde pencils a and f, and the ocular focused to the lower layer as before. The points of the upper image, which is not exactly focused, will now give much broader dissipa- tion circles projected on the sharply seen points A,* B,* but the centres of the two sets of points will still coincide.

24 Transactions of the Society.

What is the difference between these two cases? ‘The small dissipation circles in the first case may still be capable of affording a pretty distinct vision of the upper layer at the same time as the lower, and we say that the depth of the object is within the range of the depth of distinct vision for pencils of narrow aperture. The broad dissipation circles resulting from the wide pencils of the full aperture will in all probability render the image of the upper layer very indistinct, so that the image of the whole object will appear indistinct also. The causa efficcens of this indistinctness is simply too great a depth of the object compared with the small depth of vision attendant upon a wider aperture. If we take a similar solid object, but of much smaller depth, we should see its upper and lower layers in sufficient distinctness, notwithstanding the wide aperture.

Consequently the indistinctness of an object which is not quite flat if observed with a wide aperture, does not arise from any dissimilarity of the images by axial and by oblique pencils, but solely on account of the reduction of the depth of vision.

Suppose now (3) an image projected by narrow oblique pencils am and 8 m through a marginal or intermediate part of the aperture. The sharp images of both layers A B and A,, B,, will be exactly the same as the sharp images by the axial pencils aaand 8a, or the sharp images by the whole pencils a and £. But as these images occur at different planes they will show a parallactic displacement. If the ocular and the eye are focused to the level of A,* B,*, the points A* and B* will appear projected to the pomts a* b* and will be seen as dissipation circles with those points as centres. We have once more always similar images, only displaced horizontally.

This must give rise to a mode of projection of solid objects which is essentially different from the ordinary perspective projec- tion under oblique vision. Suppose the die (fig. 1) delineated at an oblique direction of 60°. A true perspective image, such as

would be obtained by an eye receiving it in Fie. 6. the direction 7, or if the Microscope were ites directed to it in this direction, would give <-~-- the projection on a ground plane perpen- ye dicular to the line r. But the image of the die as depicted by the oblique pencils in an objective of 120° aperture-angle will be a projection to a ground plane perpen- ) dicular to the auis of the Microscope (fig. 6), and not to the rays 7. Both surfaces, a b and ¢ d, will therefore be projected with their true diameter, but displaced horizontally, and not shortened as in fig. 1. If we compare now the image of the solid object by the oblique

On the Mode of Vision with Wide Apertures. By Prof. Abbe. 25

pencils a m and 8 m to the image by the axial pencils a a and 8 a, or to the image by other oblique pencils (say of opposite obliquity), we have dissimilar images. But this dissimilarity relating solely to the projection of successive layers, and being nothing else but different parallactic displacement of successive layers, cannot be effective in microscopic vision unless these images are produced by different portions of the aperture separately, that is, if the effective pencils (or the effective portions of the aperture) are separated, and the one conducted to one image and the other to another image, as is done by the various arrangements for stereoscopic vision. As long as various portions of the aperture are effective at the same tume, producing one image, we have only an increase of the dissipation circles at those planes which are not exactly focused, and a reduction consequently of the depth of distinct vision. We have no “all-round vision” because vision ceases as soon as the “all-round ” becomes effective.

The result of the whole consideration therefore is:—(1) Ina well-corrected (or aplanatic) objective the images of a flat object by pencils of different obliquity are always strictly similar. The obliquity of the rays at the object does not produce any difference of perspective, as it does in ordinary vision, or when the same object is observed by a Microscope in an oblique direction. The Microscope therefore does not delineate solid objects perspectively, and has no capacity of all-round vision, either as a drawback or a benefit.

(2) The images of solid objects arise from the projection of their successive layers in perfect similarity, however large the aperture may be (refraction of the rays by structural parts within the layers disregarded). As long as the depth of the object is within the limits of the depth of vision corresponding to the aperture and amplification in use, we obtain a distinct parallel projection of all successive layers on one common plane perpen- dicular to the axis of the Microscope (a regular ground plan), either strictly orthogonal (fig. 7) when the delineating pencils, narrow or wide, are Fig. 7. axial, or with a certain obliquity of pro- =~ (aaa jection if these pencils G.e. the axes or | | {| | f ie / principal rays of the pencils) are inclined to the axis of the Microscope. If the depth of the preparation is greater than the depth of tolerably distinct vision, this projection must become indistinct, because the layers above or below the range of distinct vision give rise to broad dissipation circles confounding with the distinct portion of theimage. Since the depth of vision, other circumstances being equal, decreases with increasing aperture, good “definition” of wide apertures is confined to thinner objects than good definition of narrow apertures.

26 Transactions of the Society.

(3) Dissimilarity of the images of solid objects by different parts of the aperture is solely difference of projection (orthogonal pro- jection versus oblique projection—or one degree of obliquity by axial pencils against an opposite obliquity by oblique pencils). It relates therefore exclusively to the manner in which successive _ layers are seen projected to the common ground plane (per- pendicular to the axis of the Microscope) or to the perception of the depth, and not in any way to the delineation of the plane layers themselves. The effectiveness of this dissimilarity for micro- Scopic véston is confined to the case of an actual separation of the images by stereoscopic apparatus; for if this dissimilarity should be perceptible and the partial images not separated (viewed by distinct eyes), the out-of-focus layers would appear confused, and no vision of the depth could be possible, as explained just above. We have, then, no advantage from the said dissimilarity.

(4) Stereoscopic vision in the Microscope is entirely based on the said dissimilarity of projection exhibited by the different parallactic displacements of the images of successive layers on the common ground plane of projection. There is no true perspective difference of the images by different portions of the aperture, because the microscopic image does not admit of a perspective shortening of the lines, which are oblique to the direction of the delineating pencils.

( 27 )

SUMMARY

OF OURRENT RESEARCHES RELATING TO

ZOOLOGY AND BOTANY (principally Invertebrata and Cryptogamia),

MICROSCOPY, &c.,

INCLUDING ORIGINAL COMMUNICATIONS FROM FELLOWS AND OTHERS.*

ZOOLOGY.

A. GENERAL, including Embryology and Histology of the Vertebrata.

Influence of Gravity on Cell-division.t—Dr. E. Pfliiger’s experi- ments were conducted with the eggs of the frog. Hach egg consists of a dark and a light hemisphere, and after fertilization the dark hemisphere always comes to lie uppermost, the “axis” of the egg being therefore vertical. When the black hemisphere is uppermost the line connecting its middle point with the middle point of the white hemisphere is termed the “ primary axis”; to the primary axis correspond, of course, a primary equator and meridian. The “secon- dary axis” passes through the point at which the first and second planes of cleavage cut each other. The “tertiary axis” finally is any perpendicular diameter of the egg that is not coincident with either of the two former axes. The first two cleavages pass through the axis of the egg, and the third cuts it at a right angle; the question therefore arises, is there any real connection between the direction of cleavage and the axis of the egg, or do the first cleavages pass through the axis of the egg because it happens to coincide with the direction of gravity? By preventing the rotation of the eggs, by fixing them to a watch-glass in various positions after fertilization, Dr. Pfliiger was able to show that the latter interpretation is the correct one; the first cleavages do not follow the axis of the egg but the direction of gravity passes along the vertical diameter, whether it happens to coincide with the axis or not. In the normal egg left to assume its own proper position with the dark hemisphere uppermost, it is well known that the process of division is far more energetic in the upper dark hemisphere, and this was believed to depend upon

* The Society are not to be considered responsible for the views of the authors of the papers referred to, nor for the manner in which those views may be expressed, the main object of this part of the Journal being to present a summary of the papers as actually published, so as to provide the Fellows with a guide to the additions made from time to time to the Library. Objections and corrections should therefore, for the most part, be addressed to the authors. (The Society are not intended to be denoted by the editorial ‘* we.”)

+ Pfliiger’s Arch. f. gesammt. Physiol., xxxi. (1883) pp. 311-8.

28 SUMMARY OF CURRENT RESEARCHES RELATING TO

some property special to this hemisphere. If, however, an egg be turned upside down during the process of division, it is found that the cleavage proceeds more vigorously in what is now the upper half and ceases to be so well marked in the lower half, and therefore clearly has nothing whatever to do with any special quality of different portions of the egg itself, but depends entirely upon its position.

Another point to which Dr. Pfliiger directed his researches was the relation that exists between the first cleavage and the axis of the future embryo; the experiments made appeared to show that the two are identical, and that each of the two cells therefore formed by the first division corresponds to one half of the body of the future embryo: and also, a fact of the greatest importance, that the various parts of the body appeared to arise from the light or dark hemispheres according to the position of these latter; when the light hemisphere was uppermost the whole nervous invagination was seen to be clear and transparent. This part of the subject, however, the author does not consider to be as yet placed on a firm basis and intends to continue his investigations.

In a second paper on the same subject * the author notes that among the tadpoles developed from the eggs some were remarkable by the dorsal surface being entirely free of pigment, owing to the fact that the light hemisphere had been fixed in the uppermost position; later, however, the pigment seemed to spread over the whole body, and no recognizable difference between the dorsal and ventral surfaces could be detected. The albinos also showed occa- sional abnormalities and soon died. A further investigation was- made upon the eggs of Bombinator igneus ; the main results appear to be the following: Quite normal embryos were developed when the upper hemisphere had a larger clear portion; but if it became almost entirely made up of the clear hemisphere the embryos were abnormal and died, though it was perfectly evident that the axis of the egg might be at any angle whatever with the direction of gravity, and not interfere in the least with the early developmental stages.

In the earlier communication it was stated that the axis of the embryo coincided with the axis of the first cell-division, and that the central nervous system was formed out of the dark or the clear hemi- sphere, or out of both according to their position; a more careful investigation has shown that the central nervous system is always developed from the clear hemisphere.

This fact appears to show that the egg is after all not “isotropous, and that a given organ arises from some particular region of the egg entirely independently of gravity; but another series of facts tends towards the opposite conclusion; in eggs fixed in an abnormal position the anus of Rusconi was never to be seen upon the upper hemisphere ; again, when the primary axis was inclined at an angle the medullary groove was always developed with the anterior end in the upper portion and the posterior end in the lower portion of the white hemisphere, which latter, of course, was also obliquely

* Pfliiger’s Arch. f. gesammt. Physiol., xxxii, (1883) pp. 1-79 (2 pls.).

ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 29

inclined to the horizontal. The position of the anus of Rusconi affords still further proof of a “ relative isotropy ” ; it always appears upon the white hemisphere, and is intimately connected with the direction of the axes of the egg.

The paper concludes with some observations on the development of Marsilia made by Dr. H. Leitgeb; it appears that in the embryo of this plant, the position of the first divisional septum in every case coincides with the axis of the archegonium ; it is, however, capable of rotation round the latter, and as soon as the axis of the archegonium ceases to be vertical, takes such a position that the embryo is divided into an upper and lower half.

The occurrence of the same principle of development in two such widely different types is evidently an indication of its wide-spread importance.

Influence of Physico-Chemical Agencies upon the Development of the Tadpoles of Rana esculenta.*—E. Yung subjected tadpoles just hatched to the action of saline solutions of various strengths. ‘The salts employed were obtained by the evaporation of the water of the Mediterranean, and the larve were placed in solutions of 1, 3, 5, 7, and 9 per 1000, which were renewed at the same time in all the vessels, and the whole were in other respects placed under precisely the same conditions. As a general result, M. Yung states that the tadpoles are developed the more slowly the more considerable the degree of saltness of the water. In the solution of 9 : 1000 no trans- formation took place, though some tadpoles live long enough to acquire hind limbs. In a solution of 10: 1000 very young tadpoles die in a few hours: elder ones survive for a few days. The author remarks upon the importance of placing equal numbers of individuals in each vessel in experiments of this kind, as their development is found to be slower in proportion to the number living together.

M. Yung also subjected young tadpoles, which normally live in quiet water, to continuous agitation in a vessel containing two litres of water regularly renewed and suitable food. Under these conditions the eges developed well; but the newly hatched tadpoles, being too feeble to seize their prey in so disturbed a medium, died of hunger, unless care was taken to give them daily a few moments of repose to take their food. If these tadpoles be compared, at different periods, with others of the same brood developing in quiet water, it is found that the developing of the former is slower, that they are less pig- mented, which indicates bad nutrition, and, lastly, that their tails are relatively more developed, especially in width, which is explained by the greater use they are obliged to make of the organs in struggling against the waves.

Colours of Feathers.t—The colours of the feathers of birds are of two kinds: (1) Objective, that is, colours caused by the presence of definite pigment, or by structural peculiarities of the feather itself, or

* Arch. Sci. Phys. et Nat., x. (1883) p. 347. See Ann. and Mag. Nat. Hist., xiii. (1884) p. 72. + Proc. Zool. Soc. Lond., 1882, p. 409.

30 SUMMARY OF CURRENT RESEARCHES RELATING TO

finally by both causes combined ; (2) Subjective colours are caused by the various effects of broken or reflected light.

The colours owing to the presence of pigment are always black, - brown, and red of various shades; only one instance is known of a green colour produced by pigment, and that is in the feathers of the Touracous. The violet and blue tints are never due to pigment alone, and often depend merely upon lines and grooves on the surface of the feather. There are numerous colours which appear to be due to the combination of definite pigmentary bodies within the substance of the feather, and the structure of the feather itself, and this is the case especially with blue feathers. If one of the blue feathers of a Macaw be pressed and broken so as to destroy its structure it appears to be of a brownish grey colour, which is owing to the presence of pig- ment of that colour. Dr. H. Gadow has published some interesting observations upon these colours. He finds that the blue feathers of many birds consist of an outer structureless sheath, beneath which is a layer of “cones” covered by a system of extremely fine lines running parallel with the long axis of the cone; below these cones lies a layer of brownish-yellow pigment, which appears black when present in great quantity. The whole surface coating of the feather varies not only in different birds, but in the different feathers of the same bird, and is in any ease too thick to allow of the blue colour being explained in the way that other colours are produced by thin plates. The fine ridges upon the cones seem to be the source of the blue colour.

The colours of yellow feathers are sometimes due simply to the presence of yellow pigment; but since many yellow feathers contain no pigment, this explanation will not hold in every case. In all pro- bability a system of fine lines observed upon the outer surface of the feather is the cause. Similar lines occur in violet feathers, but they are finer and not quite so straight, and in this way, perhaps, the difference in colour is produced.

With regard to the green colour of many feathers, the suggestion of Krukenberg, that it is caused by an admixture of yellow pigment and a blue optical structural colour, is not a sufficient explanation in- asmuch as most green feathers do not show the same peculiar structures that are met with in blue feathers. All the green feathers examined show the following structure: a transparent smooth sheath covers the barbs and barbules ; beneath this is a system of ridges and fine pits ; the ridges are less regular than those of the yellow coloured feathers ; beneath this layer is yellowish or brownish pigment.

The second group of colours (subjective) are produced by a transparent sheath which acts as a prism. They are the so-called “metallic” colours, which change according to the position from which they are viewed. In describing the colours of birds a good deal of confusion has arisen from this fact, and Dr. Gadow suggests the desirability of introducing a standard method of describing these metallic colours in order to insure uniformity, and gives a diagram illustrating three positions in which the bird should be placed in order to describe its colours.

ZOOLOGY AND BOTANY, MIOROSCOPY, ETO. 31

Rudimentary Sight apart from eyes.*—Prof. V. Graber has in- stituted experiments to ascertain whether, and if so to what extent, eyeless and blinded animals are sensitive to light. As an example of the former he chose the earthworm ; for the latter, Triton cristatus.

The worms were placed in a box containing a number of cells of equal size, each with front and hind wall made of glass; the whole box was further divided into three parts, each of which had two front and two hind windows; the latter were turned from the light; and one of the windows of each cell was darkened, or supplied with a differently coloured light from that of the others. At the bottom of each was placed a layer of mud not sufficient to conceal earthworms. Twenty to thirty worms were first put into each cell and the box placed with one side towards a window with a north light. The number of worms found on the light and the dark sides respectively were counted at the end of every hour, and were replaced by fresh every four hours. Seven readings show that 40 specimens were found in the light, and 210 in the darkened spaces, giving a proportion of five of the latter to two of the former.

Using opaque glass for one set of windows, 326 worms were found in the partitions thus relatively darkened, and 204 in the absolutely light ones. In employing light of different colours, care was taken that the one colour chosen should be very decidedly lighter than the other. As it soon became evident that red was more attractive to the worms than blue, a much darker shade of blue was chosen than that of the red; then in 12 divisions 193 specimens were found in the pale red light, and only 57 in the dark blue; this difference is the more remarkable as the worms, being naturally lovers of darkness, would, so far as intensity of light was concerned, have been expected to prefer the dark blue; it indicates an apprecia- tion of the quality of the light. In like manner, white light, deprived of the ultra-violet rays, attracted 87, ordinary white light only 13 worms; of pale green and dark blue, the former colour attracted 138, the latter 42 individuals ; of pale red and dark green, the former attracted 168, the latter only 72. In examination of a statement, that it is only the anterior end of the body which is sensitive to light, experiments were made upon worms deprived of this part to a length of four or five rings; they gave the proportion of worms found in the dark as 2°6 to 1 of those in the light, and that of those in red light as 2-8 to 1 of those in the blue—results tending in the same direction as those obtained from entire specimens. Applying the same method to newts, Graber found that while, of 160 uninjured specimens, only one was found in the light area, the rest being in the dark, 185 specimens from which the eyeballs together with a con- siderable length of the optic nerves had been removed, were found in the light, and 308 in the dark. The same result was obtained after the filling up of the eye-cavity by wax in some of the blinded animals, proving that the optic nerve had no action in producing this light-sensitiveness. Using coloured light, it was found that 192

* SB. K. Akad. Wiss. Wien, Ixxxvii. (1883) p. 201. Of. Naturforscher, xvi. (1883) pp. 437-9, and ‘ Journ. of Science,’ v. (1883) pp. 727-32.

32 SUMMARY OF CURRENT RESEARCHES RELATING TO

normal specimens appeared to prefer pale red against the 8 in dark blue ; of blind individuals, 536 were found in the first, and 406 in the latter colour; with colours of about equal intensity, 474 were found in the red, and 176 in the blue.

The proportion of individuals preferring a good light devoid of ultra-violet rays was as 2 to 1 of those found in darkish ultra-violet light; as between green and blue, the proportion was 38 to 1 of the respective colours for unblinded, and about 13 to 1 for blinded in- dividuals. Thus blinded animals are shown to be sensitive to both quantitative and qualitative differences in light.

Graber considers the above facts to be in accordance with the theory of evolution of special optical organs (eyes) from generalized ones (skin); as the reactions of these hypothetical dermal organs resemble those of the former, and their inferior activity is quite natural. This agreement favours the interpretation of the phenomena as due to an inferior degree of vision, and not to the results of thermal or chemical influences acting on the animals experimented on.

B. INVERTEBRATA.

Nerve-centres of Invertebrata.* —W. Vignal has examined the nervous system of various groups of the higher invertebrates and comes to the following, among other, conclusions :-—

In the Crustacea the cells of the ganglia are nearly all unipolar, and almost always consist of a viscous granular substance, in which the nucleus is slightly and the nucleoli highly refractive. Bipolar and multipolar cells are also present. The nerve-fibres forming the connectives, the commissures, and the nerves have a proper wall, on the surface or in the interior of which there are oval nuclei; the inclosed substance is viscid and slightly granular, and contains a central bundle of fibrils, or the fibrils are isolated. The central nerve-chain and the nerves are invested in two sheaths, one of which is structureless, and appears to be of a cuticular nature, while the other is formed of imbricated lamellae, which, in the macrourous crustacea, forms a partition in the connectives. The nerye-cells on the ventral face of a ganglion send off prolongations into its centre ; this centre is formed of nerve-fibres, and of prolongations from the cells; the two are closely united and form a plexus whence the nerves are given off. The gastro-intestinal nerves are composed of fine fibres which have the same structure as those of the ventral chain. They form two plexuses, along which nerve-cells are to be observed.

In the Mollusca bipolar or multipolar cells are very rarely found among the cells of the ganglia, and this is especially the case in the Gasteropoda. ‘The nerve-cells are formed of a ganglionic globe on the surface, and in the interior there are fine fibrils ; among these are fine fatty granulations, which are sometimes variously coloured. The ganglionic globe, which has no investing membrane, contains a large nucleus and one or more nucleoli. The nerves and connectives are formed by fibres of very various sizes, which are separated from one

* Arch, Zool. Exper. et Gén., i. (1883) pp. 267-408 (4 pls.).

ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 83

another by partitions developed from the sheath of the nerve. The fibres themselves are made up of fibrils which are inclosed in a slightly refractive and feebly granular substance. The myenteric plexus forms, along the digestive tube, a triple plexus, on the branches of which ganglionic cells are irregularly scattered. ‘The centre of the ganglia is formed by a fibrillar substance and a slightly refractive body, which is of the same nature as the peripheral matter of the cells; the central fibrils have no definite arrangement; the nerves arise from the centre of them. The envelope of the nervous system is formed by a lamellar connective tissue, which is composed of fine fibrils. Among the cells of the ganglia a peculiar kind of connective cell was observed ; this was oval, and contained a large nucleus; from the two poles of the cell long fibrils are given off.

In the Hirudinea all the ganglionic nerve-cells are unipolar ; those of the gastro-intestinal system have the same essential structure but are not invested in a proper membrane, the sheath that invests them being part of that system which has been compared by Ranvier to Henle’s sheath in vertebrates. The fibres that make up the nerves vary in size, and are separated from one another by thick partitions, and are composed of fibrils inclosed in a slightly granular protoplasm. The sympathetic system forms a double plexus along the digestive tube, and on its branches are developed ganglionic cells. The con- nective chain is formed by three nervous cylinders; no nuclei are to be seen either in the protoplasm of the connectives or of the nerves. No multipolar nerve-cells are to be found in the centre of the ganglia, as Walter and Hermann have imagined. The investment of the nervous system is a continuous sheath which is only open near the ends of the nerves.

The last group dealt with is that of the Oligocheeta, and in it we find that the nerve-cells of the cerebral and ventral ganglia are mostly unipolar, and are formed of a viscous slightly granular substance. Near the homogeneous nucleus fatty granulations are to be found. Bipolar and multipolar cells are also to be observed, but they do not occupy any definite position. The nerve-fibres form the columns of the chain, have no proper walls, but are simply bounded by the par- titions of connective tissue; these tubes are formed of a viscous and almost homogeneous substance, which is only feebly coloured by osmic acid; these fibres anastomose with one another.

The giant nerve-tubes are three in number, and extend along almost the whole length of the chain. The central, which is the largest, commences at the middle of the first ganglion, and the other two at the second; they end at the terminal ganglia. They appear to have no relation to the nerve-fibres.

The nerves have the same structures as the fibres of the columns.

The whole system (with the exception of the cerebral ganglia) is completely invested in three sheaths—epithelial, muscular, and struc- tureless (of a cuticular character); the first and third are alone formed on the cerebral ganglia.

All the ventral ganglia give off three nerves on either side. The first is very sharply distinguished into two halves.

Ser. 2.—Vot. IY. D

34 SUMMARY OF CURRENT RESEARCHES RELATING TO

Tracks of Terrestrial and Fresh-water Animals.*—T. M‘K. Hughes describes some peculiar markings on mud, the manner of formation of which he has been able to observe, and points out how they explain away difficulties which have arisen in the interpretation of certain fossil tracks, showing that some of the characters most relied upon to prove the vegetable origin of the fossil forms, such as branching, solid section, &c., could be produced by animals.

His observations were made on certain pits in the district about Cambridge which are filled with the fine mud produced in washing out the phosphatic nodules from the Cambridge greensand. As the water gradually dries up, a surface of extremely fine calcareous mud is exposed. This deposit is often very finely laminated, and occa- sionally among the lamine old surfaces can be discovered, which, after having been exposed for some time to the air, had been covered up by a fresh inflow of watery mud into the pit. The author describes the character of the cracks made in the process of drying, and the results produced when these were filled up. He also describes the tracks made by various insects, indicating how these are modified by the degree of softness of the mud, and points out the differences in the tracks produced by insects with legs and elytra, and by annelids, such as earthworms. The marks made by various worms and larve which burrow in the mud are also described. Marks resembling those called Nerettes and Myrianites are produced by a variety of animals. The groups of ice-spicules which are formed during a frosty night also leave their impress on the mud. The author expresses the opinion that Cruziana, Nereites, Crossopodia, and Paleo- chorda are mere tracks, not marine vegetation, as has been suggested in the case of the first, or, in the second, the impression of the actual body of ciliated worms.

Growth of Carapace of Crustacea and of Shell of Mollusca.j— A notice is here given of T. Tullberg’s essay on this subject,t in which he states that the carapace of the lobster is formed by the subjacent cells, the outer part of which becomes directly converted into the hard covering; the striation is due to the fibres being im- bedded in the fundamental substance ; these fibres are formed by the cells at the time when the enveloping substance is deposited.

On the other hand, the shell of the Mollusca is, for the most part, a secretion from the celis of the mantle, but there is, in addition, a substance which in structure calls to mind the carapace of the lobster, where, too, the outer part of the cells gives rise to the shell-substance. The operculum of the whelk appears to be formed in the same way as its shell.

The researches have been carried on in too few species to justify any general conclusions, but if we take into consideration the great resemblance which obtains between all chitinous formations, it hardly seems rash to suppose that they are all formed like the carapace of

* Abstr. Proc. Geol. Soc. Lond., 1883, No. 448, pp. 10-11. + Arch. Zool. Expér. et Gén., i. (1883) pp. xi—xiv. { In K. Svenska Vetens.-Akad. Handl., xix. (1882).

a ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 35

the lobster, while the great resemblance between the shells of Lamelli- branchs and Gasteropods almost justifies the belief that their mode of formation is essentially the same.

Commensalism between a Fish and a Medusa.*—In a consign- ment from the Mauritius, G. Lunel found united Caranz melampygus and Crambessa palmipes. ‘The fish stuck with the greater part of its body in the apertures which are formed by the four columns uniting the stomach with the nectocalyx, and traversed by the gastro-vascular canals. This union could not be explained by the hypothesis that the animal had sought out the other as its prey and means of nourishment. For the medusa belongs to a family which possesses no proper oral aperture, but only a series of microscopic pores, which can only take in very finely divided nourishment, and the fish had merely taken up his quarters in a natural hollow of the medusa, which was only enlarged, but in no way injured, by the long residence of the fish.

It was ascertained that the fisherman had taken the two animals together in that position; and that several years ago there had been seen on the coast, in a depth of about six inches below the surface, a fish of the same kind in conjunction with an anemone, and going in and out of it. The anemone into which the fish had entered was living, for it could be seen moving.

Lunel arrives at the conclusion that there are certain kinds of fish the fully grown individuals of which live at more or less considerable depths, whilst the young, either on account of an unknown peculiarity of their organization, or because they require a diet more congenial to their age, ascend with particular meduse to the upper regions of